SUPPORTING INFORMATION The Greening of Peptide ...Boc-(R)-Ala-OH (164 mg, 0.87 mmol) and HCl.H-Phe-OBn (250 mg, 0.87 mmol) were coupled according to the general coupling procedure

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SUPPORTING INFORMATION

The Greening of Peptide Synthesis.

Stefan B. Lawrenson, Roy Arav and Michael North*

A dataset of the spectra recorded during the course of this project can be downloaded from:

DOI: 10.15124/56c29a3e-d3d0-4958-8063-3d8464c2d44f

Table of ContentsGeneral experimental procedures S4

Characterizing data for compounds 5-12 S61H NMR spectrum of Boc-Ala-Phe-OBn 5a S2813C NMR spectrum of Boc-Ala-Phe-OBn 5a S291H NMR spectrum of Boc-(R)-Ala-Phe-OBn 5a' S3013C NMR spectrum of Boc-(R)-Ala-Phe-OBn 5a' S311H NMR spectrum of Boc-Leu-Phe-OBn 5b S3213C NMR spectrum of Boc-Leu-Phe-OBn 5b S331H NMR spectrum of Boc-(R)-Leu-Phe-OBn 5b' S3413C NMR spectrum of Boc-(R)-Leu-Phe-OBn 5b' S351H NMR spectrum of Boc-Met-Val-OBn 5c S3613C NMR spectrum of Boc-Met-Val-OBn 5c S371H NMR spectrum of Boc-Asp(OBn)-Val-OBn 5d S3813C NMR spectrum of Boc-Asp(OBn)-Val-OBn 5d S391H NMR spectrum of Boc-Aib-Leu-OBn 5e S4013C NMR spectrum of Boc-Aib-Leu-OBn 5e S411H NMR spectrum of TFA.H-Ala-Phe-OBn 6a S4213C NMR spectrum of TFA.H-Ala-Phe-OBn 6a S431H NMR spectrum of TFA.H-Leu-Phe-OBn 6b S44

Electronic Supplementary Material (ESI) for Green Chemistry.This journal is © The Royal Society of Chemistry 2017

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13C NMR spectrum of TFA.H-Leu-Phe-OBn 6b S451H NMR spectrum of TFA.H-Met-Val-OBn 6c S4613C NMR spectrum of TFA.H-Met-Val-OBn 6c S471H NMR spectrum of TFA.H-Asp(OBn)-Val-OBn 6d S4813C NMR spectrum of TFA.H-Asp(OBn)-Val-OBn 6d S491H NMR spectrum of TFA.H-Aib-Leu-OBn 6e S5013C NMR spectrum of TFA.H-Aib-Leu-OBn 6e S511H NMR spectrum of Boc-Leu-Ala-Phe-OBn 7a S5213C NMR spectrum of Boc-Leu-Ala-Phe-OBn 7a S531H NMR spectrum of Boc-(R)-Leu-Ala-Phe-OBn 7a' S5413C NMR spectrum of Boc-(R)- Leu-Ala-Phe-OBn 7a' S551H NMR spectrum of Boc-Gly-Leu-Phe-OBn 7b S5613C NMR spectrum of Boc-Gly-Leu-Phe-OBn 7b S571H NMR spectrum of Boc-Ser(OBn)-Met-Val-OBn 7c S5813C NMR spectrum of Boc-Ser(OBn)-Met-Val-OBn 7c S591H NMR spectrum of Boc-Trp-Asp(OBn)-Val-OBn 7d S6013C NMR spectrum of Boc-Trp-Asp(OBn)-Val-OBn 7d S611H NMR spectrum of Boc-Pro-Aib-Leu-OBn 7e S6213C NMR spectrum of Boc-Pro-Aib-Leu-OBn 7e S631H NMR spectrum of TFA.H-Leu-Ala-Phe-OBn 8a S6413C NMR spectrum of TFA.H-Leu-Ala-Phe-OBn 8a S651H NMR spectrum of TFA.H-Gly-Leu-Phe-OBn 8b S6613C NMR spectrum of TFA.H-Gly-Leu-Phe-OBn 8b S671H NMR spectrum of TFA.H-Ser(OBn)-Met-Val-OBn 8c S6813C NMR spectrum of TFA.H-Ser(OBn)-Met-Val-OBn 8c S691H NMR spectrum of TFA.H-Trp-Asp(OBn)-Val-OBn 8d S7013C NMR spectrum of TFA.H-Trp-Asp(OBn)-Val-OBn 8d S711H NMR spectrum of TFA.H-Pro-Aib-Leu-OBn 8e S7213C NMR spectrum of TFA.H-Pro-Aib-Leu-OBn 8e S731H NMR spectrum of Boc-Gly-Leu-Ala-Phe-OBn 9a S7413C NMR spectrum of Boc-Gly-Leu-Ala-Phe-OBn 9a S751H NMR spectrum of Boc-Ala-Gly-Leu-Phe-OBn 9b S7613C NMR spectrum of Boc-Ala-Gly-Leu-Phe-OBn 9b S771H NMR spectrum of Boc-Lys(Z)-Ser(OBn)-Met-Val-OBn 9c S7813C NMR spectrum of Boc-Lys(Z)-Ser(OBn)-Met-Val-OBn 9c S79

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1H NMR spectrum of Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d S8013C NMR spectrum of Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d S811H NMR spectrum of Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e S8213C NMR spectrum of Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e S831H NMR spectrum of Boc-Leu-Ala-Phe-OH 10a S8413C NMR spectrum of Boc-Leu-Ala-Phe-OH 10a S851H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solution-phase synthesis S8613C NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solution-phase synthesis S871H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solid-phase synthesis in DMF S881H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solid-phase synthesis in PC S891H NMR spectrum of HCl.H-Ala-Phe-OBn (in CD3OD) prepared in PC S90

HPLC traces of diastereomeric peptides 5a and 5a' S91

HPLC traces of diastereomeric peptides 5b and 5b' S93

HPLC traces of diastereomeric peptides 7a and 7a' S94

HPLC-UV-HRMS of Bradykinin S95

References S98

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General experimental procedures

Instrumentation

All experiments were carried out under an atmosphere of N2. Analytical TLC was performed on

aluminum backed plates pre-coated (0.25 mm) with Merck KGaA silica Gel 60 F254. Compounds

were visualized by exposure to UV light and stained using potassium permanganate solution

(KMnO4) followed by heating. Flash column chromatography was performed using Flurochem

Silica Gel LC60A (40-60 μM). All solvent mixtures are reported as v/v solutions. All reagents were

purchased from either Sigma Aldrich or Fluorochem and were used as received unless otherwise

stated. Propylene carbonate and DMF were reagent grade (99%) and were used without additional

purification. PE refers to the fraction of petroleum ether boiling between 40 and 60 °C. All amino

acid derivatives have S-configuration unless stated otherwise.

1H- and 13C-NMR spectra were obtained using a JEOL ECS 400 MHz spectrometer at ambient

temperature (unless specified otherwise). Both 1H and 13C spectra were referenced to the residual

protic solvent (CHCl3 = 7.26 ppm, CH3OH = 4.78 ppm, (CH3)2SO = 2.50 ppm). Coupling constants

are reported using the following notation or combination of: s = singlet, br= broad, d = doublet, t =

triplet, q = quartet, quin = quintet, sex = sextet, sept = septet, oct = octet, non = nonet, m =

multiplet). Assignment of signals in 1H and 13C spectra were performed using 1H-1H COSY, DEPT-

135 and 1H-13C HSQC, where appropriate.

High resolution mass spectra (HRMS) were recorded using ESI, on a Bruker micrOTOF MS in

tandem with an Agilent series 1200 LC system. All IR data was obtained using a Perkin Elmer

Spectrum Two FT-IR spectrometer. Optical rotations were obtained using a Jasco DIB370 digital

polarimeter, all concentrations are given in g/100 mL. Melting points were determined with a Stuart

SMP3 melting point apparatus and are uncorrected.

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Chiral normal phase HPLC was performed using a Daicel Chiralcel OD column (4.6 × 250 mm × 5

μm) fitted with a Chiralpak 1A (5 μm) guard column (4 × 10 mm) and monitored using a DAD on

an Agilent Infinity 1220 LC system equipped with Agilent OpenLab software. Flow rate: 0.7 mL

min-1, 97:3 Hexane: i-PrOH, detection at 210 and 254 nm.

Bradykinin samples were analysed on the Bruker microTOF mass spectrometer in tandem with an

Agilent series 1200 LC system with an additional diode array detector. Chromatography was carried

out at 40 oC on a Waters Sunfire C18 column (3.5 μm packing, 2.1 mm x 100 mm) with a solvent

flow rate of 0.2 mL min-1 and UV detection at 214 nm. A dual solvent system was employed:

Solvent A: MeCN + 0.1% formic acid

Solvent B: water + 0.1% formic acid

The solvent system was varied following the sequence: 10% A / 90% B for 5 minutes, then ramp to

50% A / 50% B over the next 10 minutes, hold at 50% A / 50% B for 5 minutes then ramp back to

10% A / 90% B. The times given in Figure 1 and page 94-96 of the supplementary information are

delayed by 5 minutes due to the time taken for the solvent to pass through the pumps, column, mass

spectrometer and UV-vis detector.

Microwave reactions were carried out in a G10 microwave vial equipped with a rare Earth stirrer

bar, using an Anton Paar Monowave 300 microwave reactor. The temperature was held at 70 °C

(monitored using a ruby thermometer) for the duration of the reaction.

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Characterizing data for compounds 5-11

Boc-Ala-Phe-OBn 5aS1

Boc-Ala-OH (324 mg, 1.71 mmol) and HCl.H-Phe-OBn (500 mg, 1.71 mmol) were coupled

according to the general coupling procedure. The residue was purified using flash column

chromatography (35:65, EtOAc:PE) to give Boc-Ala-Phe-OBn 5a as a white crystalline solid (682

mg, 93%). RF = 0.34 (40:60, EtOAc:PE); mp 95.6-96.3 °C; [α]D23 -27.7 (c 1.0 in MeOH); IR (Neat)

νmax 3347 (m), 3063 (w), 3029 (w), 2928 (m), 2852 (w), 1735 (w), 1684 (w) 1666 (w) and 1521 (s)

cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.36-7.31 (m, 3H, ArH), 7.29-7.24 (m, 2H, ArH), 7.26-7.21

(m, 3H, ArH), 7.04-6.97 (m, 2H, ArH), 6.72 (d J 7.7 Hz, 1H, Phe-NH), 5.16-5.10 (m, 1H, Ala-NH),

5.13 (d J 12.1 Hz, 1H, OCH2Ph), 5.07 (d J 12.1 Hz, 1H, OCH2Ph), 4.88 (dt, J 7.7, 5.9 1H, Phe-

NCH), 4.11 (br, 1H, Ala-NCH), 3.13 (dd J 13.9, 6.1 Hz, 1H, CH2Ph), 3.08 (dd J 13.9, 6.1 Hz, 1H,

CH2Ph), 1.41 (s, 9H, C(CH3)3), 1.29 (d J 6.6 Hz, 3H, CH3); 13C NMR (100 MHz, CDCl3): δ = 172.3

(C=O), 171.2 (C=O), 155.6 (NC=O), 135.7 (ArC), 135.1 (ArC), 129.5 (ArCH), 128.7 (ArCH),

128.6 (ArCH), 127.2 (ArCH), 80.2 (CMe3), 67.4 (OCH2Ph), 53.3 (Phe-NCH), 50.3 (Ala-NCH),

38.0 (CH2Ph), 28.4 (C(CH3)3), 18.5 (CH3); MS (ESI) m/z 449 [(M+Na)+, 100]; HRMS (ESI) m/z

calculated for C24H30N2O5Na 449.2048 (M+Na)+, found 449.2047 (0.6 ppm error).

Boc-(R)-Ala-Phe-OBn 5a'

Boc-(R)-Ala-OH (164 mg, 0.87 mmol) and HCl.H-Phe-OBn (250 mg, 0.87 mmol) were coupled


chromatography (40:60, EtOAc:PE) to give Boc-(R)-Ala-Phe-OBn 5a' as an off-white solid (323

mg, 87%). RF = 0.38, (40:60, EtOAc:PE); mp 75.4-76.2 °C; [α]D23 6.5 (c 1.0 in MeOH); IR (Neat)

νmax3294 (m), 3066 (w), 3030 (w), 2977 (m), 2930 (m), 1717 (m), 1687 (m) and 1648 (s) cm-1; 1H

NMR (400 MHz, CDCl3): δ = 7.39-7.32 (m, 3H, ArH), 7.32-7.27 (m, 2H, ArH), 7.25-7.16 (m, 3H,

ArH), 7.06-6.98 (m, 2H, ArH), 6.80 (br, 1H, Phe-NH), 5.15 (d J 12.4 Hz, 1H, OCH2Ph), 5.11 (br,

1H, Ala-NH), 5.08 (d J 12.4 Hz, 1H, OCH2Ph), 4.90 (dt J 7.7, 6.2 Hz, 1H, Phe-NCH), 4.20 (br, 1H,

S7

Ala-NCH), 3.13 (dd J 13.9, 6.0 Hz, 1H, CH2Ph), 3.07 (dd J 13.9, 6.0 Hz, 1H, CH2Ph), 1.42 (s, 9H,

C(CH3)3), 1.27 (d J 7.1 Hz, 3H, CH3); 13C NMR (100 MHz, CDCl3): δ = 172.3 (C=O), 171.3

(C=O), 155.6 (NC=O), 135.7 (ArC), 135.2 (ArC), 129.4 (ArCH), 128.8 (ArCH), 128.7 (ArCH),

128.6 (ArCH), 127.2 (ArCH), 80.3 (CMe3), 67.4 (OCH2Ph), 53.2 (Phe-NCH), 50.1 (Ala-NCH),

38.0 (CH2Ph), 28.4 (C(CH3)3), 18.5 (CH3); MS (ESI) m/z 449 [(M+Na)+, 20], 427 [(M+H)+, 100];

HRMS (ESI) m/z calculated for C24H31N2O5 427.2155 (M+H)+, found 427.2227 (-0.3 ppm error).

Boc-Leu-Phe-OBn 5bS2

Boc-Leu-OH (100 mg, 0.43 mmol) and HCl.H2N-Phe-OBn (110 mg, 0.43 mmol) and were coupled


chromatography (40:60, EtOAc:PE) to give Boc-Leu-Phe-OBn 5b as a white powder (162 mg,

80%). RF = 0.42 (30:70, EtOAc:PE); mp 100.8-102.1 °C (lit.S2 103–105 oC); [α]D23 -27.4 (c 1.0 in

MeOH) [lit.S2 -33.8 (c 1.0 in MeOH)]; IR (Neat) νmax 3339 (m), 3064 (w), 3034 (w), 2956 (w), 2935

(w), 2879 (w), 1731 (s), 1679 (m), 1665 (s) and 1518 (s) cm-1; 1H NMR (400 MHz, CDCl3): δ =

7.39-7.34 (m, 3H, ArH), 7.29-7.26 (m, 2H, ArH), 7.22-7.19 (m, 3H, ArH), 7.03-7.01 (m, 2H, ArH),

6.53 (d J 7.6 Hz, 1H, Phe-NH), 5.15 (d J 12.0 Hz, 1H, OCH2Ph), 5.10 (d J 12.0 Hz, 1H, OCH2Ph),

4.88 (dt J 7.7, 6.0 Hz, 1H, Phe-NCH), 4.86 (br, 1H, Leu-NH), 4.08 (br, 1H, Leu-NCH), 3.14 (dd J

14.0, 6.4 Hz, 1H, CH2Ph), 3.09 (dd J 14.0, 6.4 Hz, 1H, CH2Ph), 1.68-1.58 (m, 2H, CH2CHMe2),

1.43 (s, 9H, C(CH3)3), 1.45-1.35 (m, 1H, CH(Me)2), 0.90 (d J 6.4 Hz, 3H, CH(CH3)2), 0.89 (d J =

6.4 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.3 (C=O), 171.2 (C=O), 155.6

(NC=O), 135.7 (ArC), 135.1 (ArC), 129.5 (ArCH), 128.7 (ArCH), 128.6 (ArCH), 127.2 (ArCH),

80.1 (CMe3), 67.4 (OCH2Ph), 53.3 (Phe-NCH), 53.2 (Leu-NCH), 41.4 (CH2CHMe2), 38.0 (CH2Ph),

28.4 (C(CH3)3), 24.8 (CHMe2), 23.0 (CH(CH3)2), 22.0 (CH(CH3)2); MS (ESI) m/z 491 [(M+Na)+,

100]; HRMS (ESI) m/z calculated for C27H37N2O5 469.2697 (M+H)+, found 469.2691 (1.2 ppm

error).

S8

Boc-(R)-Leu-Phe-OBn 5b'S3

Boc-(R)-Leu-OH (100 mg, 0.43 mmol) and HCl.H2N-Phe-OBn (110 mg, 0.43 mmol) and were

coupled according to the general coupling procedure. The residue was purified using flash column

chromatography (20:80-30:70, EtOAc:PE) to give Boc-(R)-Leu-Phe-OBn 5b' as a white powder

(187 mg, 92%). RF = 0.48 (30:70, EtOAc:PE); mp 96.2-97.4 °C (lit.S3 97 oC); [α]D23 +4.8 (c 1.0 in

MeOH); IR (Neat) νmax 3334 (m), 3064 (w), 3031 (w), 2961 (w), 1739 (m), 1726 (m), 1686 (m),

1652 (s) and 1519 (s) cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.39-7.34 (m, 3H, ArH), 7.31-7.28 (m,

2H, ArH), 7.22-7.19 (m, 3H, ArH), 7.04-7.00 (m, 2H, ArH), 6.61 (d J 6.4 Hz, 1H, Phe-NH), 5.17 (d

J 12.0 Hz, 1H, OCH2Ph), 5.10 (d J 12.4 Hz, 1H, OCH2Ph), 4.89 (dt, J 7.9, 6.0 Hz, 1H, Phe-NCH),

4.78 (d J 6.8 Hz, 1H, Leu-NH), 4.17-4.05 (m, 1H, Leu-NCH), 3.13 (dd J 14.0, 6.0 Hz, 1H, CH2Ph),

3.08 (dd, J 14.0, 6.4 Hz, 1H, CH2Ph), 1.65-1.50 (m, 2H, CH2CHMe2), 1.42 (s, 9H, C(CH3)3), 1.41-

1.30 (m, 1H, CH2CHMe2), 0.88 (d J 6.0 Hz, 6H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ =

172.3 (C=O), 171.3 (C=O), 155.7 (NC=O), 135.7 (ArC), 135.1 (ArC), 129.4 (ArCH), 128.8

(ArCH,), 128.7 (ArCH,), 128.6 (ArCH), 127.2 (ArCH), 80.2 (OCMe3), 67.4 (OCH2Ph), 53.2 (Phe-

NCH), 53.1 (Leu-NCH), 41.3 (CH2CHMe2), 38.0 (CH2Ph), 28.4 (C(CH3)3), 24.8 (CHMe2), 23.0

(CH(CH3)2), 21.9 (CH(CH3)2); MS (ESI) m/z 491 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C27H37N2O5 469.2697 (M+H)+, found 469.2694 (0.2 ppm error).

Boc-Met-Val-OBn 5cS4

Boc-Met-OH (374 mg, 1.5 mmol) and H2N-Val-OBn (569 mg, 1.5 mmol) and were coupled


chromatography (30:70, EtOAc:PE) to give Boc-Met-Val-OBn 5c as a clear oil (603 mg, 91%). RF

= 0.33 (30:70, EtOAc); [α]D23 -25.1 (c 1.0 in MeOH); IR (Neat) νmax 3314.7 (w), 2968 (w), 2932

(w), 1739 (m), 1658 (s) and 1521 (m) cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.39-7.29 (m, 5H,

ArH), 6.72 (d J 8.2 Hz, 1H, Val-NH), 5.23 (br, 1H, Met-NH), 5.19 (d J 12.4 Hz, 1H, OCH2Ph),

5.12 (d J 12.4 Hz, 1H, OCH2Ph), 4.56 (dd J 8.8, 4.7 Hz, 1H, Val-NCH), 4.31 (dt, J 7.3, 7.1 Hz, 1H,

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Met-NCH), 2.58 (t J 7.2 Hz, 2H, CH2CH2SMe), 2.21 (dsep, J 7.0, 4.6 Hz, 1H, CHMe2), 2.09 (s, 3H,

SCH3), 2.03 (dt, J 14.0, 7.1 Hz, 1H, CH2CH2SMe), 1.95 (dt J 14.0, 7.1 Hz, 1H, CH2CH2SMe), 1.43

(s, 9H, C(CH3)3), 0.91 (d, J 7.0 Hz, 3H, CH(CH3)2), 0.86 (d J 7.0 Hz, 3H, CH(CH3)2); 13C NMR

(100 MHz, CDCl3): δ = 171.6 (C=O), 171.5 (C=O), 155.6 (NC=O), 135.4 (ArC), 128.7 (Ar-CH),

128.6 (Ar-CH), 128.5 (Ar-CH), 80.2 (CMe3), 67.2 (OCH2Ph), 57.3 (Val-NCH), 53.3 (Met-NCH),

31.3 (CH2SMe), 31.2 (CHMe2), 30.2 (CH2CH2SMe), 28.4 (C(CH3)3), 19.1 (CH(CH3)2), 17.6

(CH(CH3)2), 15.2 (CH2SCH3); MS (ESI) m/z 477 [(M+K)+, 15], 461 [(M+Na)+, 100]; HRMS (ESI)

m/z calculated for C22H34N2NaO5S 461.2086 (M+Na)+, found 461.2081 (-2.2 ppm error).

Boc-Asp(OBn)-Val-OBn 5dS5

Boc-Asp(OBn)-OH (808 mg, 2.5 mmol) and H2N-Val-OBn para-toluenesulfonate (949 mg, 2.5

mmol) were coupled according to the general coupling procedure. The residue was purified using

flash column chromatography (25:75, EtOAc:PE) to give Boc-Asp(OBn)-Val-OBn 5d as a pale

yellow oil (897 mg, 70%). RF = 0.29 (25:75, EtOAc:PE); [α]D23 -28.4 (c 1.0 in MeOH) [lit.S5 -33.3

(c 1.07 in MeOH)]; IR (Neat) νmax 3332 (w), 3033 (w), 2967 (w), 2934 (w), 1734 (s), 1679 (s) and

1517 (m) cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.40-7.29 (m, 10H, ArH), 7.07 (d J 8.9 Hz, 1H,

NH), 5.75 (d J 8.2 Hz, 1H, NH), 5.19 (d J 12.0, 1H, OCH2Ph), 5.17-5.08 (m, 3H, 3×OCH2Ph) 4.61-

4.50 (m, 2H, 2×NCH), 3.03 (dd J 17.2, 4.7 Hz, 1H, CH2CO2) 2.71 (dd J 17.2, 4.7 Hz, 1H,

CH2CO2), 2.26-2.12 (m, 1H, CHMe2), 1.45 (s, 9H, C(CH3)3), 0.91 (d J 6.9 Hz, 1H, CH(CH3)2), 0.86

(d J 6.9 Hz, 1H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.1 (C=O), 171.4 (C=O), 170.8

(C=O), 155.8 (NC=O), 13.5 (CAr), 135.4 (CAr), 128.7 (ArCH), 128.6 (ArCH), 128.5 (ArCH),

128.4 (ArCH), 128.3 (ArCH), 80.6 (CMe3), 67.1 (OCH2Ph), 67.0 (OCH2Ph), 57.5 (Val-NCH), 50.7

(Asp(OBn)-NCH), 36.0 (CH2CO2), 31.3 (CHMe2), 28.4 (C(CH3)3), 19.1 (CH(CH3)2), 17.6

(CH(CH3)2); MS (ESI) m/z 535 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for C28H36N2NaO7

535.2429 (M+Na)+, found 535.2417 (-0.1 ppm error).

S10

Boc-Aib-Leu-OBn 5eS6

Boc-Aib-OH (508 mg, 2.5 mmol) and H2N-(S)-Leu-OBn p-toluenesulfonate (934 mg, 2.5 mmol)

were coupled according to the general coupling procedure. The residue was purified using flash

column chromatography (30:70, EtOAc:PE) to give Boc-Aib-Leu-OBn 5e as a white powder (794

mg, 78%). RF = 0.25 (25:75, EtOAc:PE); mp 93.8-94.5 °C; [α]D23 -16.3 (c 0.5 in MeOH); IR (Neat)

νmax 3308 (m), 2953 (m), 2869 (w), 1720 (m), 1685 (s), 1659 (s), 1534 (m) and 1507 (s) cm-1; 1H

NMR (400 MHz, CDCl3): δ = 7.39-7.29 (m, 5H, ArH), 6.88 (br, 1H, NH), 5.16 (d J 12.4 Hz, 1H,

OCH2Ph), 5.11 (d J 12.4 Hz, 1H, OCH2Ph), 4.89 (br, 1H, NH), 4.66-4.60 (m, 1H, NCH), 1.72-1.56

(m, 3H, CH2CHMe2), 1.49 (s, 3H, C(CH3)2), 1.45 (s, 3H, C(CH3)2), 1.42 (s, 9H, C(CH3)3), 0.91 (d J

6.6 Hz, 3H, CH(CH3)2), 0.89 (d J 6.6 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 174.5

(C=O), 173.0 (C=O), 154.7 (NC=O), 135.6 (ArC), 128.7 (ArCH), 128.5 (ArCH), 128.3 (ArCH),

77.4 (OCMe3), 67.1 (OCH2Ph), 56.9 (NCMe2), 50.9 (NCH), 41.7 (CH2CHMe2), 28.4 (C(CH3)3),

26.3 (CH2CHMe2), 24.8 (C(CH3)2), 23.0 (CH(CH3)2), 21.9 (CH(CH3)2); MS (ESI) m/z 429

[(M+Na)+, 100]; HRMS (ESI) m/z calculated for C22H34N2NaO5 429.2365 (M+Na)+, found

429.2373 (-2.7 ppm error).

TFA.H-Ala-Phe-OBn 6aS7

Boc-Ala-Phe-OBn (340 mg, 0.8 mmol) was deprotected according to the general procedure for Boc

deprotections to give TFA.H-Ala-Phe-OBn 6a as an off white solid (351 mg, 99%). Mp 180.7-

181.3 °C; [α]D23 -8.1 (c 0.5 in MeOH); IR (Neat) νmax 3333 (m), 3165 (w), 3031 (w), 2938 (w), 1725

(s), 1660 (s), 1547 (m) and 1523 (m) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.40-7.15 (m, 10H,

ArH), 5.16 (d J 12.1 Hz, 1H, OCH2Ph), 5.11 (d J 12.1 Hz, 1H, OCH2Ph), 4.76 (dd, J 8.9, 5.8 1H,

Phe-NCH), 3.86 (q J 6.8 Hz, 1H, Ala-NCH), 3.20 (dd J 14.1, 5.9 Hz, 1H, CH2Ph), 2.98 (dd J 14.1,

5.9 Hz, 1H, CH2Ph), 1.42 (d J 6.9 Hz, 3H, CH3); 13C NMR (100 MHz, CD3OD): δ = 172.4 (C=O),

171.1 (C=O), 137.9 (ArC), 136.9 (ArC), 130.2 (ArCH), 129.6 (ArCH), 129.6 (ArCH), 129.6

(ArCH), 129.5 (ArCH), 128.0 (ArCH), 68.2 (OCH2Ph), 55.6 (Phe-NCH), 50.0 (Ala-NCH), 38.1

S11

(CH2Ph), 17.6 (CH3); MS (ESI) m/z 349 [(M+Na)+, 50], 327 [(M+H)+, 100]; HRMS (ESI) m/z

calculated for C19H23N2O3 327.1709 (M-CF3CO2-)+, found 327.1695 (2.3 ppm error).

TFA.H-Leu-Phe-OBn 6bS8

Boc-Leu-Phe-OBn (600 mg, 1.28 mmol) was deprotected according to the general procedure for

Boc deprotections to give TFA.H-Leu-Phe-OBn 6b as an off white solid (1.33 g, 99%). Mp 172.7-

173.5 °C; IR (Neat) νmax 2960 (w), 2485 (w), 1731 (s), 1723 (s), 1679 (m), 1674 (s), 1665 (s) and

1518 (s) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.35-7.30 (m, 3H, ArH), 7.29-7.23 (m, 4H, ArH),

7.22-7.16 (m, 3H, ArH), 5.12 (d J 12.0 Hz, 1H, OCH2Ph), 5.08 (d J 12.0 Hz, 1H, OCH2Ph), 4.74

(dd J 8.8, 6.0 Hz, 1H, Phe-NCH), 4.59 (br, 1H, NH), 3.77 (dd J 8.8, 6.0 Hz, 1H, Leu-NCH), 3.18

(dd J 14.0, 6.4 Hz, 1H, CH2Ph), 3.01 (dd J 14.0, 8.8 Hz, 1H, CH2Ph), 1.73-1.53 (m, 2H,

CH2CHMe2), 0.91 (d J 6.4 Hz, 3H, CH(CH3)2), 0.90 (d J 6.4 Hz, 3H, CH(CH3)3); 13C NMR (100

MHz, CD3OD): δ = 172.3 (C=O), 170.9 (C=O), 137.9 (ArC), 136.9 (ArC), 130.2 (ArCH), 129.6

(ArCH), 129.6 (ArCH), 129.6 (ArCH), 129.5 (ArCH), 128.0 (ArCH), 68.2 (OCH2Ph), 55.7 (Phe-

NCH), 52.7 (Leu-NCH), 41.7 (CH2CHMe2), 38.0 (CH2Ph), 25.2 (CH(Me)2), 23.2 (CH(CH3)2), 21.8

(CH(CH3)2); MS (ESI) m/z 391 [(M+Na)+, 35], 369 [(M+H)+, 100]; HRMS (ESI) m/z calculated for

C22H29N2O3 369.2173 (M-CF3CO2-)+, found 369.2173 (0.3 ppm error).

TFA.H-Met-Val-OBn 6c

Boc-Met-Val-OBn (603 mg, 1.37 mmol) was deprotected according to the general procedure for

Boc deprotections to give TFA.H-Met-Val-OBn 6c as a white solid (474 mg, 80%). Mp 169.6-

170.1 °C; [α]D23 -10.0 (c 1.0 in MeOH); IR (Neat) νmax 3344 (w), 2975 (w), 1693 (s), 1663 (s), 1544

(m) and 1518 (m) cm-1; 1H NMR (400 MHz, DMSO-d6): δ = 8.74 (d J 7.9 Hz, 1H, NH), 8.20 (br,

3H, NH3+), 7.41-7.32 (m, 5H, ArH), 5.16 (d J 12.0 Hz, 1H, OCH2Ph), 5.13 (d J 12.0 Hz, 1H,

OCH2Ph), 4.26 (dd J 7.5, 6.1 Hz, 1H, Val-NCH), 3.97 (t J 6.2 Hz, 1H, Met-NCH), 2.50-2.44 (m,

2H, CH2SMe), 2.19-2.06 (m, 1H, CHMe2), 2.01 (s, 3H, SCH3), 2.02-1.89 (m, 2H, CH2CH2SMe),

0.91 (d J 6.8 Hz, 3H, CH(CH3)2), 0.90 (d J 6.8 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, DMSO-

S12

d6): δ = 170.9 (C=O), 168.9 (C=O), 135.7 (ArC), 128.5 (ArCH), 128.2 (ArCH), 128.1 (ArCH), 66.2

(OCH2Ph), 57.8 (Val-NCH), 51.4 (Met-NCH), 31.2 (CH2CH2SMe), 29.7 (CHMe2), 28.0

(CH2SMe), 18.9 (CH(CH3)2), 18.0 (CH(CH3)2), 14.5 (SCH3); MS (ESI) m/z 361 [(M+Na)+, 50],

339 [(M+H)+, 100]; HRMS (ESI) m/z calculated for C17H27N2O3S 339.1742 (M-CF3CO2-)+, found

339.1737 (2.9 ppm error).

TFA.H-Asp(OBn)-Val-OBn 6dS5

Boc-Asp(OBn)-Val-OBn (747 mg mg, 1.46 mmol) was deprotected according to the general

procedure for Boc deprotections to give TFA.H-Asp(OBn)-Val-OBn 6d as an off-white solid (650

mg, 85%). Mp 147.8-148.4 °C; [α]D23 -16.0 (c 1.0 in MeOH); IR (Neat) νmax 3328 (m), 3032 (w),

2976 (w), 2884 (w), 2586 (w), 1734 (m), 1705 (s), 1661 (s), 1558 (m) and 1519 (w) cm-1; 1H NMR

(400 MHz, DMSO-d6): δ = 8.77 (d J 8.2 Hz, 1H, NH), 8.34 (br, 3H, NH3+), 7.46-7.27 (m, 10H,

ArH), 5.20-5.07 (m, 4H, 2×OCH2Ph), 4.33-4.24 (m, 2H, 2×NCH), 2.88 (dd J 17.6, 3.9 Hz, 1H,

CH2CO2Bn), 2.78 (dd J 17.6, 8.9 Hz, 1H, CH2CO2Bn) 2.11 (oct J 6.7 Hz, 1H, CHMe2), 0.89 (d J

7.3 Hz, 3H, CH(CH3)2), 0.87 (d J 7.3 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, DMSO-d6): δ =

170.7 (C=O), 169.1 (C=O), 168.9 (C=O), 135.7 (ArC), 135.6 (ArC), 128.5 (ArCH), 128.5 (ArCH),

128.3 (ArCH), 128.3 (ArCH), 128.2 (ArCH), 66.4 (OCH2Ph), 66.3 (OCH2Ph), 57.8 (Val-NCH),

48.6 (Asp-NCH), 35.5 (CH2CO2Bn), 29.8 (CHMe2), 18.9 (CH(CH3)2), 17.9 (CH(CH3)2); MS (ESI)

m/z 435 [(M+Na)+, 75], 413 [(M+H)+, 100]; HRMS (ESI) m/z calculated for C23H29N2O5 413.2076

(M-CF3CO2-)+, found 413.2060 (3.5 ppm error).

TFA.H-Aib-Leu-OBn 6eS6

Boc-Aib-Leu-OBn (100 mg, 0.25 mmol) was deprotected according to the general procedure for

Boc deprotections to give TFA.H-Aib-Leu-OBn 6e as a yellow oil (102 mg, 97%). IR (Neat) νmax

2960 (w), 1728 (m), 1661 (s) and 1530 (m) cm-1; 1H NMR (400 MHz, DMSO-d6): δ = 8.59 (d J 8.3

Hz, 1H, NH), 8.23 (s, 3H, NH3+), 7.42-7.31 (m, 5H, ArH), 5.13 (d J 12.9 Hz, 1H, OCH2Ph), 5.10 (d

J 12.9 Hz, 1H, OCH2Ph), 4.44-4.37 (m, 1H, Leu-NCH), 1.77-1.52 (m, 3H, CH2CHMe2), 1.48 (s,

S13

3H, C(CH3)2), 1.45 (s, 3H, C(CH3)2), 0.90 (d J 6.1 Hz, 3H, CH(CH3)2), 0.83 (d J 6.1 Hz, 3H,

CH(CH3)2); 13C NMR (100 MHz, DMSO-d6): δ = 172.0 (C=O), 171.9 (C=O), 135.8 (ArC), 128.5

(ArCH), 128.2 (ArCH), 127.9 (ArCH), 66.2 (OCH2Ph), 56.4 (Aib-NC), 50.8 (Leu-NCH), 39.3

(CH2CHMe2), 24.4 (CHMe2), 23.4 (C(CH3)2), 23.3 (C(CH3)2), 22.8 (CH(CH3)2), 20.9 (CH(CH3)2);

MS (ESI) m/z 329 [(M+Na)+, 50], 307 [(M+H)+, 100]; HRMS (ESI) m/z calculated for C17H27N2O3

307.2022 (M-CF3CO2-)+, found 307.2008 (2.0 ppm error).

Boc-Leu-Ala-Phe-OBn 7a

Boc-Leu-OH (185 mg, 0.8 mmol) and TFA.H2N-Ala-Phe-OBn (352 mg, 0.8 mmol) were coupled


chromatography (35:65-60:40, EtOAc:PE) to give the Boc-Leu-Ala-Phe-OBn 7a as a white solid

(325 mg, 75%). RF = 0.35 (60:40, EtOAc:PE); mp 143.9-144.6 °C; [α]D23 -37.4 (c 1.0 in MeOH); IR

(Neat) νmax 3326 (m), 2955 (w), 1983 (w), 1730 (m), 1688 (m), 1639 (s) and 1523 (m) cm-1; 1H

NMR (400 MHz, CDCl3): δ = 7.38-7.29 (m, 3H, ArH), 7.29-7.22 (m, 2H, ArH), 7.21-7.13 (m, 3H,

ArH), 7.04-6.91 (m, 2H, ArH), 6.65 (d J 7.1 Hz, Ala-NH), 6.59 (d J 7.0 Hz, Phe-NH), 5.14 (d J

12.0 Hz, 1H, OCH2Ph), 5.06 (d J 12.0 Hz, 1H, OCH2Ph), 4.90 (br, 1H, Leu-NH), 4.87 (dt J 7.5, 6.9

Hz, 1H, Phe-NCH), 4.46 (q J 7.2 Hz, 1H, Ala-NCH), 4.09 (br, 1H, Leu-NCH), 3.10 (dd J 14.2, 6.6

Hz, CH2Ph), 3.05 (dd J 14.2, 6.6 Hz, CH2Ph), 1.70-1.58 (m, 1H, CHMe2), 1.59-1.51 (m, 2H,

CH2CHMe2), 1.42 (s, 9H, OC(CH3)3), 1.29 (d, J 7.2 Hz, 3H, NCHCH3), 0.90 (d J 6.6 Hz, 6H,

CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.6 (C=O), 171.8 (C=O), 171.2 (C=O), 155.8

(NC=O), 135.7 (ArC), 135.1 (ArC), 129.3 (ArCH), 128.7 (ArCH), 128.6 (ArCH), 127.2 (ArCH),

80.2 (OCMe3), 67.4 (OCH2Ph), 53.5 (Phe-NCH), 53.0 (Leu-NCH), 48.9 (Ala-NCH), 41.2

(CH2CHMe2), 37.9 (CH2Ph), 28.4 (OC(CH3)3), 24.8 (CH(CH3)2), 23.2 (CH(CH3)2), 21.9 (CHMe2),

18.3 (NCHCH3); MS (ESI) m/z 562 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C30H41N3NaO6 540.3074 (M+Na)+, found 562.2888 (-1.3 ppm error).

S14

Boc-(R)-Leu-Ala-Phe-OBn 7a'

Boc-(R)-Leu-OH (69 mg, 0.3 mmol) and TFA.H2N-Ala-Phe-OBn (164 mg, 0.3 mmol) were


chromatography (30:20:50-40:20:40, EtOAc:CH2Cl2:PE) to give Boc-(R)-Leu-Ala-Phe-OBn 7a' as

a white solid (132 mg, 82%). RF = 0.18 (30:20:50, EtOAc:CH2Cl2:PE); mp 131.7-132.5 °C; [α]D23 -

9.3 (c 1.0 in MeOH); IR (Neat) νmax 3319 (m), 3277 (m), 2930 (w), 1730 (m), 1686 (m), 1638 (s)

and 1528 (s) cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.37-7.32 (m, 3H, ArH), 7.29-7.24 (m, 2H,

ArH), 7.23-7.18 (m, 3H, ArH), 7.05-7.00 (m, 2H, ArH), 6.67 (br, 1H, Phe-NH), 6.60 (d J 7.6 Hz,

1H, Ala-NH), 5.14 (d J 12.3 Hz, 1H, OCH2Ph), 5.08 (d J 12.3 Hz, 1H, OCH2Ph), 4.88-4.78 (m, 2H,

Leu-NH + Phe-NCH), 4.50 (q J 7.3 Hz, 1H, Ala-NCH), 4.06 (br, 1H, Leu-NCH), 3.12 (dd J 14.0,

5.1 Hz, 1H, CH2Ph), 3.05 (dd J 14.0, 5.1 Hz, 1H, CH2Ph), 1.69-1.55 (m, 3H, CH2CHMe2), 1.43 (s,

9H, C(CH3)3), 1.29 (d J 6.3 Hz, 3H, NCHCH3), 0.92 (d J 6.2 Hz, 3H, CH(CH3)2), 0.91 (d J 6.2 Hz,

3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.5 (C=O), 171.8 (C=O), 171.2 (C=O), 155.8

(NC=O), 135.2 (ArC), 129.4 (ArC), 128.7 (ArCH), 128.7 (ArCH), 127.2 (ArCH), 80.3 (OCMe3),

67.4 (OCH2Ph), 53.5 (Phe-NCH), 53.3 (Leu-NCH), 48.8 (Ala-NCH), 41.3 (Leu-CH2CHMe2), 34.7

(CH2Ph), 28.4 C(CH3)3), 24.9 (CH(CH3)2), 23.1 (CH(CH3)2), 22.0 (CHMe2), 18.1 (NCHCH3); MS

(ESI) m/z 562 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for C30H41N3NaO6 562.2893 (M+Na)+,

found 562.2876 (1.9 ppm error).

Boc-Gly-Leu-Phe-OBn 7bS9

Boc-Gly-OH (145 mg, 0.83 mmol) and TFA.H2N-Leu-Phe-OBn (400 mg, 0.83 mmol) were


chromatography (50:50-60:40, EtOAc:PE) to give Boc-Gly-Leu-Phe-OBn 7b as a white powder


(Neat) νmax 3295 (w), 2958 (w), 1714 (s), 1640 (s) and 1546 (m) cm-1; 1H NMR (400 MHz, CDCl3):

δ = 7.38-7.34 (m, 3H, ArH), 7.30-7.27 (m, 2H, ArH), 7.24-7.20 (m, 3H, ArH), 7.04-7.02 (m, 2H,

S15

ArH), 6.57 (d, J 7.6 Hz, 1H, Phe-NH), 6.46 (d J 8.4 Hz, 1H, Leu-NH), 5.26 (t J 5.7 Hz, 1H, Gly-

NH), 5.16 (d J 12.4 Hz, 1H, OCH2Ph), 5.10 (d J 12.4 Hz, 1H, OCH2Ph), 4.87 (dt J 8.0, 6.4 Hz, 1H,

Phe-NCH), 4.50-4.40 (m, 1H, Leu-NCH), 3.76 (dd, J 16.8, 5.6 Hz, 1H, Gly-NCH2), 3.67 (dd J 16.8,

5.2 Hz, 1H, Gly-NCH2), 3.14 (dd J 14, 6.0 Hz, 1H, CH2Ph), 3.06 (dd J 14.0, 6.4 Hz, 1H, CH2Ph),

1.65-1.54 (m, 2H, CH2CHMe2), 1.53-1.46 (m, 1H, CHMe2), 1.45 (s, 9H, OC(CH3)3), 0.87 (d J 6.0

Hz, 3H, CH(CH3)2), 0.86 (d J 6.0 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 171.6

(C=O), 171.2 (C=O), 169.6 (C=O), 156.1 (NC=O), 135.8 (ArC), 135.1 (ArC), 129.4 (ArCH), 128.7

(ArCH), 128.6 (ArCH), 128.6 (ArCH), 127.1 (ArCH), 77.4 (OC(CH3)3), 67.4 (OCH2Ph), 53.3 (Phe-

NCH), 51.6 (Leu-NCH), 44.3 (Gly-NCH2), 40.1 (CH2CHMe2), 37.9 (CH2Ph), 28.4 (OC(CH3)3),

24.7 (CH2CHMe2), 22.9 (CH(CH3)2), 22.1 (CH(CH3)2); MS (ESI) m/z 548 [(M+Na)+, 100]; HRMS

(ESI) m/z calculated for C29H39N3NaO6 548.2731 (M+Na)+, found 548.2719 (2.4 ppm error).

Boc-Ser(OBn)-Met-Val-OBn 7c

Boc-Ser(OBn)-OH (313 mg, 1.1 mmol) and TFA.H2N-Met-Val-OBn (478 mg, 1.1 mmol) were

coupled according to the general coupling procedure. The residue was then purified using flash

column chromatography (47.5:52.5, EtOAc:PE) to give Boc-Ser(OBn)-Met-Val-OBn 7c as a

colourless oil (537 mg, 83%). RF = 0.46 (47.5:52.5, EtOAc:PE); [α]D23 -26.8 (c 1.0 in MeOH); IR

(Neat) νmax 3299 (w), 2967 (w), 2930 (w), 1738 (m), 1714 (m) and 1644 (s) cm-1; 1H NMR (400

MHz, CDCl3): δ = 7.40-7.26 (m, 10H, ArH), 7.22 (d J 6.9 Hz, 1H, Met-NH), 6.79 (d J 8.4 Hz, 1H,

Val-NH), 5.38 (d J 6.0 Hz, 1H, Ser-NH), 5.19 (d J 12.4 Hz, 1H, CO2CH2Ph), 5.12 (d J 12.4 Hz, 1H,

CO2CH2Ph) 4.63 (dt J 7.6, 6.8 Hz, 1H, Met-NCH), 4.56 (d J 11.8 Hz, 1H, CH2OCH2Ph), 4.51 (d J

11.8 Hz, 1H, CH2OCH2Ph), 4.56-4.51 (m, 1H, Val-NCH), 4.29 (br, 1H, Ser-NCH), 3.91 (dd J 9.4,

3.7 Hz, 1H, CH2OBn), 3.57 (dd J 9.4, 6.0 Hz, 1H, CH2OBn) 2.54 (t J 7.1 Hz, 2H, CH2SMe), 2.24-

2.13 (m, 1H, Val-CHMe2), 2.06 (s, 3H, SCH3), 2.06-1.95 (m, 2H, CH2CH2SMe), 1.44 (s, 9H,

OC(CH3)3), 0.89 (d J 7.0 Hz, 3H, CH(CH3)2), 0.85 (d J 7.0 Hz, 3H, CH(CH3)2); 13C NMR (100

MHz, CDCl3): δ = 171.5 (C=O), 170.7 (C=O), 170.5 (C=O), 155.7 (NC=O), 137.4 (ArC), 135.4

S16

(ArC), 128.7 (ArCH), 128.6 (ArCH), 128.6 (ArCH), 128.1 (ArCH), 127.9 (ArCH), 73.6 (OCH2Ph),

69.9 (CH2OBn), 67.2 (OCH2Ph), 57.5 (Val-NCH), 54.3 (Ser-NCH) 52.4 (Met-NCH), 31.1

(CHMe2), 30.8 (CH2CH2SMe), 30.0 (CH2SMe), 28.4 (OC(CH3)2), 19.2 (CH(CH3)2), 17.7

(CH(CH3)2), 15.0 (SCH3); MS (ESI) m/z 638 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C32H45N3NaO7S 638.2876 (M+Na)+, found 638.2870 (4.2 ppm error).

Boc-Trp-Asp(OBn)-Val-OBn 7d

Boc-Trp-OH (231 mg, 0.76 mmol) and TFA.H2N-Asp(OBn)-Val-OBn (400 mg, 0.76 mmol) were


chromatography (50:50, EtOAc:PE) to give Boc-Trp-Asp(OBn)-Val-OBn 7d as a pale yellow solid


(Neat) νmax 3320 (m), 3062 (w), 2967 (w), 2932 (w), 1729 (s) and 1646 (s) cm-1; 1H NMR (400

MHz, CDCl3): δ = 8.17 (s, 1H, ArNH), 7.62 (d J 7.5 Hz, 1H, ArH), 7.40-7.27 (m, 11H, ArH), 7.19-

7.09 (m, 3H, ArH), 7.03 (d J 2.1 Hz, 1H, Asp-NH), 7.01 (d J 8.8 Hz, 1H, Val-NH), 5.18 (d J 11.8

Hz, 1H, OCH2Ph), 5.10 (d J 11.8 Hz, 1H, OCH2Ph), 5.06-5.01 (m, 3H, OCH2Ph + Trp-NH), 4.80-

4.72 (m, 1H, Asp-NCH), 4.46-4.39 (m, 2H, Val-NCH, Trp-NCH), 3.33 (dd J 14.4, 5.2 Hz, 1H, Trp-

CH2), 3.18 (dd J 14.7, 6.6 Hz, 1H, Trp-CH2), 2.91 (d J = 16.2 Hz, 1H, CH2CO2Bn), 2.36 (dd J 17.2,

6.6 Hz, 1H, CH2CO2Bn), 2.11 (oct J 6.8 Hz, 1H, CHMe2), 1.41 (s, 9H, OC(CH3)3), 0.87 (d J 6.7

Hz, 3H, CH(CH3)2), 0.78 (d J 6.7 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.2

(C=O), 172.0 (C=O), 171.4 (C=O), 170.1 (C=O), 155.6 (NC=O), 136.3 (ArC), 13.6 (ArC), 135.5

(ArC), 128.7 (ArCH), 128.6 (ArCH), 128.5 (ArCH), 128.5 (ArCH), 128.4 (ArCH), 128.4 (ArCH),

127.4 (ArC), 123.2 (ArCH), 122.5 (ArCH), 119.9 (ArCH), 118.9 (ArCH), 111.4 (ArCH), 110.3

(ArC), 80.5 (OCMe3) 67.1 (OCH2Ph), 66.9 (OCH2Ph), 57.7 (Val-NCH), 55.4 (Asp-NCH), 49.3

(Trp-NCH), 35.5 (Trp-CH2), 31.0 (CHMe2), 28.4 (C(CH3)3), 19.1 (CH(CH3)2), 17.7 (CH(CH3)2);

MS (ESI) m/z 721 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for C39H46N4NaO8 721.3213

(M+Na)+, found 721.3208 (1.8 ppm error).

S17

Boc-Pro-Aib-Leu-OBn 7e

Boc-Pro-OH (357 mg, 1.66 mmol) and TFA.H2N-Aib-Leu-OBn (700 mg, 1.66 mmol) were coupled


chromatography (2:98-5:95, MeOH:CH2Cl2) to give Boc-Pro-Aib-Leu-OBn 7e as a white powder

(618 mg, 73%). RF = 0.18, (2:98, MeOH:CH2Cl2); mp 157.5-158.1 °C; [α]D23 -51.9 (c 0.5 in

MeOH); IR (Neat) νmax 3382 (w), 3274 (w), 3060 (w), 2974 (w), 2871 (w), 1735 (m), 1681 (s), 1643

(s), 1549 (m), 1522 (m) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.40-7.22 (m, 5H, ArH), 5.17 (d J

12.6 Hz, 1H, CH2Ph), 5.11 (d J 12.6 Hz, 1H, CH2Ph), 4.57-4.44 (m, 1H, Leu-NCH), 4.18-4.07

(Pro-NCH), 3.54-3.33 (m, 2H, CH2N), 2.26-2.09 (m, 1H, CH2CH2CH2N), 2.09-1.75 (m, 3H,

CH2CH2CH2N), 1.73-1.57 (m, 3H, CH2CHMe2), 1.45 (s, 9H, OC(CH3)3), 1.43 (s, 3H, C(CH3)2),

1.41 (s, 3H, C(CH3)2), 0.91 (3H, d J 5.7 Hz, CH(CH3)2), 0.89 (3H, d J 4.8 Hz, CH(CH3)2); 13C

NMR (100 MHz, CD3OD, major rotomer): δ = 176.8 (C=O), 174.5 (C=O), 173.8 (C=O), 156.4

(NC=O), 137.3 (ArC), 129.5 (ArCH), 129.4 (ArCH), 129.3 (ArCH), 81.3 (OCMe3), 67.7

(OCH2Ph), 61.5 (Pro-NCH), 57.8 (Aib-NC), 52.5 (Leu-NCH), 47.9 (CH2N), 41.5 (CH2CH2CH2N),

31.3 (CH2CH2N), 28.9 (OC(CH3)3), 26.5 (CHMe2), 25.7 (CH2CHMe2), 25.4 (C(CH3)2), 24.5

(C(CH3)2), 23.2 (CH(CH3)2), 22.2 (CH(CH3)2); MS (ESI) m/z 526 [(M+Na)+, 100]; HRMS (ESI)

m/z calculated for C27H41N3NaO6 526.2893 (M+Na)+, found 526.2893 (-0.9 ppm error).

TFA.H-Leu-Ala-Phe-OBn 8aS10

Boc-Leu-Ala-Phe-OBn (260 mg, 0.48 mmol) was deprotected according to the general procedure

for Boc deprotections, giving TFA.H-Leu-Ala-Phe-OBn 8a as an off white solid (257 mg, 96%).

Mp 196.0-196.5 °C; [α]D23 -15.2 (c 1.0 in MeOH); IR (Neat) νmax 3394 (w), 3262 (w), 2957 (m),

1732 (w), 1648 (s) and 1516 (m) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.32-7.12 (m, 10H, ArH),

5.10 (d J 12.4 Hz, 1H, OCH2Ph), 5.06 (d J 12.4 Hz, 1H, OCH2Ph), 4.65 (dd J 7.8, 6.2 Hz, 1H, Phe-

NCH), 4.39 (q J 7.2 Hz, 1H, Ala-NCH), 3.86-3.78 (m, 1H, Leu-NCH), 3.10 (dd J 13.8, 6.1 Hz, 1H,

S18

CH2Ph), 2.99 (dd J 13.8, 6.1 Hz, 1H, CH2Ph), 1.71-1.55 (m, 3H, Leu-CH2CHMe2), 1.29 (d J 7.2

Hz, 3H, NCHCH3), 0.95 (d J 6.0 Hz, 3H, CH(CH3)2), 0.93 (d J 6.0 Hz, 3H, CH(CH3)2); 13C NMR

(100 MHz, CD3OD): δ = 174.3 (C=O), 172.6 (C=O), 172.5 (C=O), 137.8 (ArC), 136.9 (ArC), 130.3

(ArCH), 129.5 (ArCH), 129.5 (ArCH), 129.4 (ArCH), 127.9 (ArCH), 68.1 (OCH2Ph), 55.4 (Phe-

NCH), 52.8 (Ala-NCH), 50.0 (Leu-NCH), 41.7 (CH2CHMe2), 38.3 (CH2Ph), 25.3 (CHMe2), 23.1

(CH(CH3)2), 22.0 (CH(CH3)2), 18.3 (NCHCH3); MS (ESI) m/z 462 [(M-TFA+Na)+, 85], 440 [(M-

TFA+H)+, 100]; HRMS (ESI) m/z calculated for C25H33N3NaO4 462.2369 (M-TFA+Na)+, found

462.2363 (3.2 ppm error).

TFA.H-Gly-Leu-Phe-OBn 8bS9

Boc-Gly-Leu-Phe-OBn (200 mg, 0.38 mmol) was deprotected according to the general procedure

for Boc deprotections to give TFA.H-Gly-Leu-Phe-OBn 8b as an off white solid (192 mg, 94%).

Mp 185.6-186.2 °C; [α]D23 -28.4 (c 0.5 in MeOH); IR (Neat) νmax 3405 (w), 3277 (w), 2955 (w),

1721 (m), 1693 (m), 1641 (s) and 1528 (m) cm-1; 1H NMR (400 MHz, DMSO-d6): δ = 7.34-7.29

(m, 3H, ArH), 7.27-7.23 (m, 2H, ArH), 7.22-7.18 (m, 2H, ArH), 7.17-7.13 (m, 3H, ArH), 5.10 (d J

12.0 Hz, 1H, OCH2Ph), 5.06 (d J 12.0 Hz, 1H, OCH2Ph), 4.65 (dd J 8.0, 6.4 Hz, 1H, Phe-NCH),

4.42 (dd J 8.0, 6.8 Hz, 1H, Leu-NCH), 3.68 (d, J 16.0 Hz, 1H, Gly-NCH2), 3.62 (d, J 16.0 Hz, 1H,

Gly-NCH2), 3.12 (dd J 14.0, 6.0 Hz, 1H, CH2Ph), 2.99 (dd J 14.0, 8.4 Hz, 1H, CH2Ph), 1.62 (non J

6.8 Hz , 1H, CHMe2), 1.53-1.42 (m, 2H, CH2CHMe2), 0.87 (d J 8.8, 6.4 Hz, 3H, CH(CH3)2), 0.85

(d J 8.8, 6.4 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, DMSO-d6): δ = 174.5 (C=O), 172.6 (C=O),

167.0 (C=O), 138.0 (ArC), 136.9 (ArC), 130.3 (ArCH), 129.6 (ArCH), 129.5 (ArCH), 129.4

(ArCH), 127.9 (ArCH), 68.1 (CH2Ph), 55.5 (Phe-NCH), 53.0 (Leu-NCH), 42.2 (CH2CHMe2), 41.4

(Gly-NCH2), 38.2 (CH2Ph), 25.8 (CHMe2), 23.4 (CH(CH3)2), 21.9 (CH(CH3)2); MS (ESI) m/z 426

[(M-TFA+H)+, 100]; HRMS (ESI) m/z calculated for C24H32N3O4 426.2387 (M-TFA+H)+, found

426.2374 (2.6 ppm error).

S19

TFA.H-Ser(OBn)-Met-Val-OBn 8c

Boc-Ser(OBn)-Met-Val-OBn (300 mg, 0.49 mmol) was deprotected according to the general

procedure for Boc deprotections to give TFA.H-Ser(OBn)-Met-Val-OBn 8c as an off-white solid

(257 mg, 84%). Mp 137.8-138.3 °C; IR (Neat) νmax 3274 (w), 3035 (w), 2922 (w), 2964 (w), 1728

(m), 1671 (s), 1644 (s), 1553 (s) cm-1; 1H NMR (400 MHz, DMSO-d6): δ = 8.69 (d, J 8.1 Hz, 1H,

Met-NH), 8.38 (d J 7.7 Hz, 1H, Val-NH), 8.18 (br, 3H, NH3+), 7.43-7.24 (m, 10H, ArH), 5.15 (d J

12.4 Hz, 1H, CO2CH2Ph), 5.10 (d J 12.4 Hz, 1H, CO2CH2Ph) 4.66-4.53 (m, 1H, Met-NCH), 4.53 (d

J 7.7 Hz, 1H, OCH2Ph), 4.49 (d J 7.7 Hz, 1H, OCH2Ph), 4.20 (dd, J 7.9, 6.1 Hz, Val-NCH), 4.09

(dd J 6.3, 3.9 Hz, 1H, Ser-NCH), 3.75 (dd, J 10.7, 4.1 Hz, 1H, CH2OBn), 3.67 (dd J 10.7, 4.1 Hz,

1H, CH2OBn), 2.49-2.36 (m, 2H, CH2SMe), 2.12-2.02 (m, 1H, CHMe2), 2.01 (s, 3H, SCH3), 1.97-

1.72 (m, 2H, CH2CH2SMe), 0.86 (d J 6.8 Hz, 3H, CH(CH3)2), 0.85 (d J 6.8 Hz, 3H, CH(CH3)2); 13C

NMR (100 MHz, DMSO-d6): δ = 171.2 (C=O), 170.9 (C=O), 166.4 (C=O), 137.6 (ArC), 135.9

(ArC), 128.5 (ArCH), 128.3 (ArCH), 128.2 (ArCH), 128.1 (ArCH), 127.8 (ArCH), 72.5

(CH2OCH2Ph), 68.5 (CH2OBn), 66.0 (CO2CH2Ph), 57.6 (Val-NCH), 52.4 (Ser-NCH), 51.9 (Met-

NCH), 32.4 (CH2CH2SMe), 29.7 (CHMe2), 29.3 (CH2SMe), 18.9 (CH(CH3)2), 18.1 (CH(CH3)2),

14.6 (SCH3); MS (ESI) m/z 538 [(M-TFA+Na)+, 70], 516 [(M-TFA+H)+, 100]; HRMS (ESI) m/z

calculated for C27H38N3O5S 516.2532 (M-TFA+H)+, found 516.2527 (1.8 ppm error).

TFA.H-Trp-Asp(OBn)-Val-OBn 8d

Boc-Trp-Asp(OBn)-Val-OBn (100 mg mg, 0.14 mmol) was deprotected according to the general

procedure for Boc deprotections to give TFA.H-Trp-Asp(OBn)-Val-OBn 8d as a yellow solid (102

mg, 99%). Mp 78.7-79.4 °C; [α]D23 -27.0 (c 0.5, in MeOH); IR (Neat) νmax 3313 (m), 3032 (w),

2938 (w), 1693 (s), 1655 (s) and 1514 (s) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.67 (d J 7.9 Hz,

1H, ArH), 7.42-7.20 (m, 12H, ArH), 7.17-7.11 (m, 1H, ArH), 7.09-7.03 (m, 1H, ArH), 5.17 (d J

12.1 Hz, 1H, OCH2Ph), 5.12 (s, 2H, OCH2Ph), 5.09 (d J 12.1 Hz, 1H, OCH2Ph), 4.91-4.86 (m, 1H,

Asp-NCH), 4.34 (d J 5.5 Hz, 1H, Val-NCH), 4.19-4.12 (m, 1H, Trp-NCH), 3.44 (dd J 15.1, 5.3 Hz,

S20

1H, Trp-CH2), 3.18 (dd J 15.1, 8.7 Hz, 1H, Trp-CH2), 2.87 (dd, J 16.7, 5.7 Hz, 1H, CH2CO2), 2.76

(dd, J 16.7, 7.9 Hz, 1H, CH2CO2), 2.14 (oct J 6.8 Hz, 1H, CHMe2), 0.93 (d J 6.6 Hz, 3H,

CH(CH3)2), 0.91 (d, J 6.6 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CD3OD): δ = 172.5 (C=O),

172.4 (C=O), 171.6 (C=O), 170.2 (C=O), 138.3 (ArC), 137.2 (ArC), 137.1 (ArC), 129.6 (ArCH),

129.6 (ArCH), 129.5 (ArCH), 129.4 (ArCH), 129.3 (ArCH), 128.2 (ArC), 125.7 (ArCH), 122.9

(ArCH), 120.3 (ArCH), 119.1 (ArCH), 112.6 (ArCH), 107.7 (ArC), 68.0 (OCH2Ph), 67.8

(OCH2Ph), 59.5 (Val-NCH), 54.7 (Trp-NCH), 51.3 (Asp-NCH), 37.1 (CH2CO2), 31.7 (CHMe2),

28.9 (Trp-CH2), 19.5 (CH(CH3)2), 18.5 (CH(CH3)2); MS (ESI) m/z 637 [(M-TFA+K)+, 100], 621

[(M-TFA+Na)+, 60], 599 [(M-TFA+H)+, 80]; HRMS (ESI) m/z calculated for C34H38N4NaO6

621.2689 (M-TFA+Na)+, found 621.2684 (-4.0 ppm error).

TFA.H-Pro-Aib-Leu-OBn 8e

Boc-Pro-Aib-Leu-OBn (200 mg, 0.39 mmol) was deprotected according to the general procedure

for Boc deprotections to give TFA.H-Pro-Aib-Leu-OBn 8e as a yellow solid (200 mg, 97%).

Mp105.3-106.2 °C; [α]D23 -52.7 (c 0.5 in MeOH); IR (Neat) νmax 3034 (w), 2957 (w), 1735 (m),

1670 (s) and 1645 (m) cm-1; 1H NMR (400 MHz, DMSO-d6): δ = 9.50 (br, 1H, NH2+), 8.54 (s, 1H,

NHCMe2), 8.50 (br, 1H, NH2+), 7.90 (d J 7.9 Hz, 1H, NHCH), 7.41-7.29 (m, 5H, ArH), 5.11 (d J

12.5 Hz, 1H, OCH2Ph), 5.07 (d J 12.5 Hz, 1H, OCH2Ph), 4.37-4.30 (m, 1H, Leu-NCH), 4.18 (dd, J

8.2, 6.4 Hz, 1H, Pro-NCH), 3.25-3.13 (m, 2H, CH2N), 2.31-2.20 (m, 1H, 1×Pro-CH2), 1.99-1.75

(m, 3H, 3×Pro-CH2), 1.73-1.45 (m, 3H, Leu-CH2CHMe2), 1.40 (s, 3H, C(CH3)2), 1.37 (s, 3H,

C(CH3)2), 0.86 (d J 6.4 Hz, 3H, CH(CH3)2), 0.81 (d J 6.4 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz,

DMSO-d6): δ = 173.3 (C=O), 172.4 (C=O), 167.6 (C=O), 135.9 (ArC), 128.4 (ArCH), 128.1

(ArCH), 127.9 (ArCH), 65.9 (CH2Ph), 59.1 (Pro-NCH), 54.5 (Aib-NC), 50.6 (Leu-NCH), 45.9

(CH2N), 39.8 (CH2CHMe2), 29.5 (CH2CH2CH2N), 25.0 (C(CH3)2), 24.5 (C(CH3)2), 24.1 (CHMe2),

23.5 (CH2CH2N), 22.9 (CH(CH3)2), 21.2 (CH(CH3)2); MS (ESI) m/z 426 [(M-TFA+Na)+, 40], 404

S21

[(M-TFA+H)+, 100]; HRMS (ESI) m/z calculated for C22H34N3O4 404.2549 (M-TFA+H)+, found

404.2379 (-3.1 ppm error).

Boc-Gly-Leu-Ala-Phe-OBn 9a

Boc-Gly-OH (44 mg, 0.25 mmol) and TFA.H2N-Leu-Ala-Phe-OBn (140 mg, 0.25 mmol) were


chromatography (95:5, EtOAc:PE) to give Boc-Gly-Leu-Ala-Phe-OBn 9a as a white solid (109 mg,

72%). RF = 0.31 (95:5, EtOAc); mp 77.6-78.2 °C; [α]D23 -22.5 (c 1.0 in MeOH); IR (Neat) νmax

3278 (m), 3066 (w), 2957 (m), 1742 (m), 1711 (m) and 1634 (s) cm-1; 1H NMR (400 MHz, CDCl3):

δ = 7.40-7.30 (m, 5H, 3×ArCH + Phe-NH + Leu-NH), 7.28-7.23 (m, 2H, ArCH), 7.21-7.14 (m, 4H,

3×ArCH + Ala-NH), 7.07-7.00 (m, 2H, ArCH), 5.46 (br t, 1H, Gly-NH), 5.15 (d J 12.4 Hz, 1H,

OCH2Ph), 5.07 (d J 12.4 Hz, 1H, OCH2Ph), 4.96-4.87 (m, 1H, Phe-NCH), 4.75-4.63 (m, 1H, Ala-

NCH), 4.63-4.52 (m, 1H, Leu-NCH), 3.89-3.72 (m, 2H, Gly-NCH2), 3.13 (dd J 13.9, 6.0 Hz, 1H,

CH2Ph), 3.04 (dd J 13.9, 6.0 Hz, 1H, CH2Ph), 1.66-1.56 (m, 1H, CHMe2), 1.58-1.49 (m, 2H,

CH2CHMe2), 1.43 (s, 9H, OC(CH3)3), 1.32 (d J 7.0 Hz, 3H, NCHCH3), 0.91 (d J 6.0 Hz, 3H,

CH(CH3)2), 0.90 (d J 6.0 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.2 (C=O),

171.9 (C=O), 171.3 (C=O), 169.4 (C=O), 156.2 (NC=O), 136.0 (ArC), 135.2 (ArC), 129.4 (ArCH),

128.7 (ArCH), 128.6 (ArCH), 128.6 (ArCH), 127.1 (ArCH), 80.3 (OCMe3), 67.3 (OCH2Ph), 53.5

(Phe-NCH), 51.0 (Leu-NCH), 48.9 (Ala-NCH), 44.3 (Gly-NCH2), 41.9 (CH2CHMe2), 37.9

(CH2Ph), 28.4 (C(CH3)3), 23.1 (CH(CH3)2), 22.2 (CH(CH3)2), 18.6 (NCHCH3); MS (ESI) m/z 619

[(M+Na)+, 100]; HRMS (ESI) m/z calculated for C32H44N4NaO7 619.3108 (M+Na)+, found

619.3088 (2.7 ppm error).

Boc-Ala-Gly-Leu-Phe-OBn 9b

Boc-Ala-OH (35 mg, 0.19 mmol) and TFA.H2N-Gly-Leu-Phe-OBn (100 mg, 0.19 mmol) were


chromatography (80:20, EtOAc:PE) to give Boc-Ala-Gly-Leu-Phe-OBn 9b as a white powder (101

S22

mg, 91%). RF = 0.49 (80:20, EtOAc:PE); mp 119.4-120.8 °C; [α]D23 -21.8 (c 1.0 in MeOH); IR

(Neat) νmax 3287 (m), 2961 (w), 1718 (m), 1643 (s), 1564 (m) and 1510 (s) cm-1; 1H NMR (400

MHz, CDCl3): δ = 7.37-7.34 (m, 3H, ArH), 7.30-7.27 (m, 2H, ArH), 7.24-7.20 (m, 3H, ArH), 7.06-

7.04 (m, 2H, ArH), 6.79 (t J 6.2 Hz, 1H, Gly-NH), 6.76 (br d, 1H, Phe-NH), 6.70 (d J 6.3 Hz, Leu-

NH), 5.16 (d J 12.0 Hz, 1H, OCH2Ph), 5.09 (d J 12.0 Hz, 1H, OCH2Ph), 5.08 (br, 1H, Ala-NH),

4.87 (dd J 14.0, 6.4 Hz, 1H, Phe-NCH), 4.43 (dt, J 14.0, 8.8 Hz, 1H, Leu-NCH), 4.07 (quin, J 6.9

Hz, 1H, Ala-NCH), 3.99 (dd J 14.0, 6.4 Hz, 1H, Gly-NCH2), 3.79 (dd J 16.8, 5.2 Hz, 1H, Gly-

NCH2), 3.15 (dd J 14.0, 6.0 Hz, 1H, CH2Ph), 3.06 (dd J 14.0, 6.8 Hz, 1H, CH2Ph), 1.69-1.52 (m,

2H, CH2CHMe2), 1.50-1.37 (m, 1H, CHMe2), 1.44 (s, 9H, OC(CH3)3), 1.32 (d J 6.8 Hz, 3H,

NCHCH3), 0.87 (d J 6.8 Hz, 3H, CH(CH3)2), 0.85 (d J 6.8 Hz, 3H, CH(CH3)2); 13C NMR (100

MHz, CDCl3): δ = 173.7 (C=O), 171.8 (C=O), 171.5 (C=O), 169.0 (C=O), 155.8 (NC=O), 136.0

(ArC), 135.2 (ArC), 129.5 (ArCH), 128.7 (ArCH), 128.6 (ArCH), 128.5 (ArCH), 127.0 (ArCH),

77.4 (OCMe3), 67.4 (OCH2Ph), 53.4 (Phe-NCH), 52.0 (Leu-NCH), 50.7 (Ala-NCH), 43.3 (Gly-

NCH2), 40.1 (CH2CHMe2), 37.9 (CH2Ph), 28.5 (OC(CH3)3), 24.8 (CHMe2), 22.9 (CH(CH3)2), 22.1

(CH(CH3)2), 18.3 (NCHCH3); MS (ESI) m/z 619 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C32H44N4NaO7 619.3108 (M+Na)+, found 619.3098 (1.0 ppm error).

Boc-Lys(Z)-Ser(OBn)-Met-Val-OBn 9c

Boc-Lys(Z)-OH (61 mg, 0.16 mmol) and TFA.H2N-Ser(OBn)-Met-Val-OBn (100 mg, 0.16 mmol)

were coupled according to the general coupling procedure. The residue was then purified using

flash column chromatography (60:40-70:30, EtOAc:PE) to give Boc-Lys(Z)-Ser(OBn)-Met-Val-

OBn 9c as a white solid (91 mg, 65%). RF = 0.44 (70:30, EtOAc:PE); mp 75.4-75.9 °C; [α]D23 -

23.77 (c 1.0 in MeOH); IR (Neat) νmax 3282 (w), 2930 (w), 1689 (m), 1635 (s) and 1519 (s) cm-1;

1H NMR (400 MHz, CDCl3): δ = 7.46 (d J 8.3 Hz, 1H, Met-NH), 7.40-7.21 (m, 15H, ArH), 7.06-

6.93 (m, 2H, Ser-NH + Val-NH), 5.64 (d J 3.2 Hz, 1H, Lys-NH), 5.18 (d J 11.8 Hz, 1H,

CO2CH2Ph), 5.15-5.04 (m, 4H, Lys--NH + 3× CO2CH2Ph), 4.69 (dt J 8.6, 5.1 Hz, 1H, Met-NCH),

S23

4.54 (d J 11.7 Hz, 1H, OCH2Ph), 4.51 (d J 11.7 Hz, 1H, OCH2Ph), 4.51-4.42 (m, 2H, Val-NCH,

Ser-NCH), 4.07-3.99 (m, 1H, CH2OBn), 3.96-3.88 (m, 1H, Lys-NCH), 3.59 (dd, J 9.5, 4.6 Hz, 1H,

CH2OBn), 3.30-3.09 (m, 2H, CH2NH), 2.51 (t J 7.5 Hz, 2H, CH2SMe), 2.37-2.23 (m, 1H,

CH2CH2SMe), 2.20-2.10 (m, 1H, CHMe2), 2.04 (s, 3H, SCH3), 1.97-1.79 (m, 2H, CH2CH2SMe +

(CH2)3), 1.74-1.61 (m, 1H, (CH2)3), 1.56-1.36 (m, 4H, (CH2)3), 1.35 (s, 9H, OC(CH3)3), 0.90 (d J

6.9 Hz, CH(CH3)2), 0.89 (d J 6.6 Hz, CH(CH3)2); 13C NMR (100 MHz, CDCl3): δ = 172.6 (C=O),

171.4 (C=O), 171.1 (C=O), 170.0 (C=O), 157.3 (C=O), 156.8 (NC=O), 137.3 (ArC), 136.5 (ArC),

135.7 (ArC), 128.7 (ArCH), 128.6 (ArCH), 128.4 (ArCH), 128.3 (ArCH), 128.2 (ArCH), 128.1

(ArCH), 128.0 (ArCH), 80.9 (-OCMe3), 73.6 (OCH2Ph), 69.0 (CH2OBn), 66.9 (2×CO2CH2Ph),

57.7 (Val-NCH), 55.9 (Lys-NCH), 54.0 (Ser-NCH), 52.7 (Met-NCH), 39.0 ((CH2)4), 31.1 ((CH2)4),

31.0 (CHMe2), 30.5 ((CH2)4), 30.5 (CH2SMe), 29.7 (CH2CH2SMe), 28.3 (-OC(CH3)3), 22.4

((CH2)4), 19.1 (CH(CH3)2), 18.1 (CH(CH3)2), 15.2 (SCH3); MS (ESI) m/z 900 [(M+Na)+, 100];

HRMS (ESI) m/z calculated for C46H63N5NaO10S 900.4193 (M+Na)+, found 900.4188 (0.1 ppm

error).

Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d

Boc-Gln(Trt)-OH (137 mg, 0.28 mmol) and TFA.H2N-Trp-Asp(OBn)-Val-OBn (200 mg, 0.28

mmol) were coupled according to the general coupling procedure. The residue was purified using

flash column chromatography (50:50, EtOAc:PE) to give Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d

as an off white solid (166 mg, 78%). RF = 0.23 (44:55, EtOAc:PE); mp 78.7-79.4 °C; [α]D23 -27.4 (c

0.5 in MeOH); IR (Neat) νmax 3301 (m), 2967 (w), 1666 (s) and 1513 (s) cm-1; 1H NMR (400 MHz,

CDCl3): δ = 7.82 (s, 1H, NH), 7.54 (d J 8.0 Hz, 1H, ArH), 7.38-6.97 (m, 31H, 29×ArH + NH +

Asp-NH), 6.93 (d J 7.1 Hz, 1H, Val-NH), 6.86 (d J 2.4 Hz, 1H, Trp-NH), 5.60 (d J 4.9 Hz, 1H, Gln-

NH), 5.18 (d J 12.2 Hz, 1H, -OCH2Ph), 5.10 (d J 12.2 Hz, 1H, -OCH2Ph), 4.98 (s, 2H, -OCH2Ph),

4.79-4.75 (m, 1H, Asp-NCH), 4.56 (dt J 6.3, 6.0 Hz, 1H, Trp-NCH), 4.42 (dd J 8.7, 4.5 Hz, 1H,

Val-NCH), 3.91 (dd J 6.2, 6.0 Hz, 1H, Gln-NCH), 3.30 (dd J 15.1, 6.2 Hz, 1H, Trp-CH2), 3.09 (dd

S24

J 14.5, 6.2 Hz, 1H, Trp-CH2), 2.49 (dd J 16.7, 4.5 Hz, 1H, Gln-CH2CO), 2.41-2.20 (m, 3H, 1×Gln-

CH2CO, 2× CH2CO2Bn), 2.12 (oct J 6.7 Hz, 1H, CHMe2), 2.05-1.83 (m, 2H, Gln-CH2CH2CO),

1.34 (s, 9H, OC(CH3)3), 0.85 (d J 6.8 Hz, 3H, CH(CH3)2), 0.82 (d J 6.8 Hz, 3H, CH(CH3)2); 13C

NMR (100 MHz, CDCl3): δ = 172.1 (C=O), 171.6 (C=O), 171.5 (C=O), 171.3 (C=O), 170.3 (C=O),

156.1 (NC=O), 144.6 (ArC), 136.2, (ArC), 136.2 (ArC), 135.7 (ArC), 128.8 (ArCH), 128.7 (ArC),

128.6 (ArCH), 128.4 (ArCH), 128.4 (ArCH), 128.1 (ArCH), 127.3 (ArCH), 127.3 (ArCH), 123.8

(ArCH), 122.3 (ArCH), 119.8 (ArCH), 118.9 (ArCH), 111.3 (ArCH), 109.6 (ArC), 80.2 (OCMe3),

70.9 (CPh3), 66.9 (OCH2Ph), 66.7 (OCH2Ph), 57.8 (Val-NCH), 54.6 (Gln-NCH), 54.2 (Asp-NCH),

49.4 (Trp-NCH), 35.2 (Trp-CH2), 33.4 (CH2CH2CO), 31.0 (CHMe2), 28.5 (CH2CH2CO); 28.4

(C(CH3)3), 27.1 (CH2CO2Bn), 19.1 (CH(CH3)2), 17.8 (CH(CH3)2); MS (ESI) m/z 1091 [(M+Na)+,

100]; HRMS (ESI) m/z calculated for C63H68N6NaO10 1091.4895 (M+Na)+, found 1091.4889 (-0.7

ppm error).

Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e

Boc-Pro-OH (71 mg, 0.19 mmol) and TFA.H2N-Pro-Aib-Leu-OBn (100 mg, 0.19 mmol) were


chromatography (5:95, MeOH:CH2Cl2) to give Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e as a white

powder (105 mg, 72%). RF = 0.21, (4:96, MeOH:CH2Cl2); mp 117.0-117.8 °C; [α]D23 -23.0 (c 0.5,

in MeOH); IR (Neat) νmax 3318 (w), 2957 (w), 1731 (m), 1682 (s), 1634 (s) and 1510 (s) cm-1; 1H

NMR (400 MHz, DMSO-d6, 80°C): δ = 7.81 (s, 1H, Aib-NH), 7.47-7.27 (m, 11H, 10×ArH, + Leu-

NH), 7.21-7.10 (m, 2H, ArH), 6.93-6.86 (m, 2H, ArH), 6.38 (br, 1H, Tyr-NH), 5.12 (s, 2H,

OCH2Ph), 5.07 (s, 2H, OCH2Ph), 4.41-4.29 (m, 3H, 3×NCH), 3.70-3.59 (m, 1H, CH2N), 3.48-3.88

(m, 1H, CH2N), 2.96-2.68 (m, 2H, Tyr-CH2), 2.09-1.93 (m, 2H, CH2CH2CH2N), 1.91-1.78 (m, 1H,

CH2CH2N), 1.66-1.49 (m, 4H, 1×CH2CH2N + CH2CHMe2), 1.41 (s, 3H, C(CH3)2), 1.36 (s, 3H,

C(CH3)2), 1.31 (s, 9H, OC(CH3)3), 0.85 (d J 5.9 Hz, 3H, CH(CH3)2), 0.83 (d J 5.9 Hz, 3H,

S25

CH(CH3)2); 13C NMR (100 MHz, DMSO-d6, 80°C): δ = 173.9 (C=O), 172.2 (C=O), 171.1 (C=O),

170.5 (C=O), 156.9 (NC=O), 155.2 (ArC), 137.2 (CAr), 135.9 (ArC), 130.4 (ArCH), 129.8 (ArC),

128.4 (ArCH), 128.0 (ArCH), 127.8 (ArCH), 127.7 (ArCH), 127.6 (ArCH), 127.5 (ArCH), 114.4

(ArCH), 78.1 (-OCMe3), 69.1 (OCH2Ph), 65.8 (OCH2Ph), 60.1 (NCH), 55.9 (NCH), 54.0 (NCH),

50.7 (NCMe2), 49.9 (CH2N), 39.6 (CH2CH2CH2N), 35.5 (Tyr-CH2), 28.7 (CH2CHMe2), 28.2

(CHMe2), 28.1 (OC(CH3)3), 25.9 (C(CH3)2), 24.8 (CH2CH2CH2N), 24.1 (OC(CH3)2), 22.5

(CH(CH3)2), 21.8 (CH(CH3)2); MS (ESI) m/z 779 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C43H56N4NaO8 779.3996 (M+Na)+, found 779.4010 (-2.4 ppm error).

Boc-Leu-Ala-Phe-OH 10aS11

A solution of Boc-Leu-Ala-Phe-OBn (325 mg, 0.6 mmol, 1.0 eq) in methanol (5 mL) was added to

a suspension of Pd/C (10% w/w) in methanol (5 mL) under H2 (1 Bar). The resulting mixture was

stirred at room temperature for 16 h. The reaction mixture was then filtered through a short plug of

celite® and concentrated in vacuo to give Boc-Leu-Ala-Phe-OH 10a as an off-white solid (258 mg,

96%). Mp 82.4-83.1 °C; [α]D23 -13.5 (c 1.0, in MeOH); IR (Neat) νmax 3300 (m), 2958 (m), 1644 (s)

and 1514 (m) cm-1; 1H NMR (400 MHz, CD3OD): δ = 7.24-7.13 (m, 5H, ArH), 4.58 (dd J 7.6, 5.3

Hz, 1H, Leu-NCH), 4.33 (dt J 7.1, 6.8 Hz, 1H, Phe-NCH), 4.10-4.01 (m, 1H, Ala-NCH), 3.15 (dd J

13.9, 5.4 Hz, 1H, CH2Ph), 2.97 (dd J 13.9, 5.4 Hz, 1H, CH2Ph), 1.64 (sept, J 6.7 Hz, 1H, CHMe2),

1.45 (t J 7.2 Hz, 2H, CH2CHMe2), 1.40 (s, 9H, OC(CH3)3), 1.28 (d J 7.1 Hz, 3H, NCHCH3), 0.90

(d, J 6.7 Hz, 3H, CH(CH3)2), 0.88 (d J 6.7 Hz, 3H, CH(CH3)2); 13C NMR (100 MHz, CD3OD): δ =

175.3 (C=O), 174.5 (C=O), 174.4 (C=O), 157.9 (NC=O), 138.2 (ArC), 130.4 (ArCH), 129.4

(ArCH), 127.8 (ArCH), 80.6 (OCMe3), 55.2 (Leu-NCH), 54.3 (Ala-NCH), 50.1 (Phe-NCH), 42.1

(CH2CHMe2), 38.4 (CH2Ph), 28.7 (OC(CH3)3), 25.9 (CHMe2), 23.5 (CH(CH3)2), 21.8 (CH(CH3)2),

18.4 (NCHCH3); MS (ESI) m/z 472 [(M+Na)+, 100]; HRMS (ESI) m/z calculated for

C23H35N3NaO6 472.2424 (M+Na)+, found 472.2413 (1.2 ppm error).

S26

TFA.H-Leu-Ala-Phe-OH 11aS12

Acid 10a (90 mg, 0.2 mmol) was deprotected according to the general procedure for Boc

deprotections to give TFA.H-Leu-Ala-Phe-OH 11a as a white solid (90 mg, 97%). Mp 189.6-191.4

°C; IR (Neat) νmax 3265 (w), 3036 (w), 3967 (w), 2401 (w), 2344 (w), 1735 (m), 1646 (s), 1555 (w)

and 1514 (w) cm-1; 1H NMR (400 MHz, TFA-d): δ = 7.20-7.09 (m, 3H, ArH), 7.07-7.00 (m, 2H,

ArH), 5.01-4.85 (m, 1H, Phe-NCH), 4.65-4.48 (m, 1H, Ala-NCH), 4.28-4.12 (m, 1H, Leu-NCH),

3.23 (dd J 14.3, 4.3 Hz, 1H, CH2Ph), 3.01 (dd J 14.3, 8.5 Hz, 1H, CH2Ph), 1.78-1.51 (m, 3H, Leu-

CH2CHMe2), 1.32 (d J 6.3 Hz, 3H, NCHCH3), 0.87 (d J 6.0 Hz, 3H, CH(CH3)2), 0.85 (d J 6.0 Hz,

3H, CH(CH3)2); 13C NMR (100 MHz, TFA-d): δ = 178.9 (C=O), 176.0 (C=O), 172.1 (C=O), 136.6

(ArC), 131.0 (ArCH), 131.0 (ArCH), 129.9 (ArCH), 56.2 (Phe-NCH), 55.8 (Leu-NCH), 52.5 (Ala-

NCH), 42.4 (CH2CHMe2), 39.0 (CH2Ph), 26.5 (CH2CHMe2), 23.2 (CH(CH3)2), 22.2 (CH(CH3)2),

18.8 (NCHCH3); MS (ESI) m/z 372 [(M+Na)+, 20], 350 [(M+H)+, 100]; HRMS (ESI) m/z

calculated for C18H28N3O4 350.2080 (M+Na)+, found 350.2076 (-0.8 ppm error).

Solid phase synthesis of TFA.H-Leu-Ala-Phe-OH 11a

This tripeptide was prepared using the general method for solid phase synthesis starting with

ChemMatrix-HMPB-Phe-H resin and adding Fmoc-amino acids in the sequence Fmoc-Ala-OH then

Fmoc-Leu-OH. TFA.H-Leu-Ala-Phe-OH 11a prepared in this way had identical analytical data to

that prepared by solution phase synthesis.

Solid phase synthesis of Bradykinin

This nonapeptide was prepared using the general method for solid phase synthesis using

ChemMatrix-HMPB-Arg(pbf)-H resin and adding Fmoc-amino acids in the sequence Fmoc-Phe-

OH, Fmoc-Pro-OH, Fmoc-Ser(Bn)-OH, Fmoc-Phe-OH, Fmoc-Gly-OH, Fmoc-Pro-OH, Fmoc-Pro-

OH and Fmoc-Arg(pbf)-OH. After each step, successful coupling or deprotection was confirmed

using either the chloranil or Kaiser colormetric tests. After cleavage from the resin, the peptide was

S27

precipitated into cold Et2O, triturated (3×20 mL Et2O) and lyophilized to give Bradykinin as a white

powder. Reverse phase HPLC retention time 11.8 minutes. MS (ESI) m/z 1060.6 (M+H)+, 710.4,

642.3, 555.3, 530.8 (M+2H)2+; HRMS (ESI) m/z calculated for C50H75N15O11 530.787976

(M+2H)2+, found 530.786911 (-2.0 ppm error).

S28

1H NMR spectrum of Boc-Ala-Phe-OBn 5a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.5f1 (ppm)

3.01

8.96

2.00

0.91

1.04

0.74

2.04

0.97

2.02

2.98

1.93

2.95

1.27

1.29

1.30

1.43

1.75

3.06

3.08

3.10

3.11

3.12

3.13

3.15

3.17

4.14

4.86

4.87

4.88

4.89

4.89

4.91

4.96

5.09

5.12

5.14

5.17

6.53

6.55

S29

13C NMR spectrum of Boc-Ala-Phe-OBn 5a

0102030405060708090100110120130140150160170180190f1 (ppm)

18.4

5

28.4

1

37.9

5

50.3

253

.30

67.4

0

80.2

0

127.

2012

8.66

128.

7312

9.47

135.

1313

5.71

155.

58

171.

2117

2.34

S30

1H NMR spectrum of Boc-(R)-Ala-Phe-OBn 5a'

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

3.12

9.15

2.00

0.96

1.88

2.07

0.91

2.03

3.05

1.97

2.90

1.27

1.29

1.42

3.06

3.07

3.09

3.11

3.12

3.14

3.16

4.17

4.87

4.89

4.91

4.92

5.08

5.11

5.15

5.18

6.63

S31

13C NMR spectrum of Boc-(R)-Ala-Phe-OBn 5a'

0102030405060708090100110120130140150160170180190f1 (ppm)

18.5

3

28.4

2

37.9

6

50.1

153

.20

67.4

0

80.2

6

127.

2212

8.69

128.

7112

8.75

129.

4413

5.16

135.

68

155.

58

171.

3017

2.34

S32

1H NMR spectrum of Boc-Leu-Phe-OBn 5b

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.28

0.70

9.81

2.28

2.00

0.90

1.86

2.03

0.93

2.01

3.02

2.07

2.92

0.88

0.89

0.90

0.90

1.26

1.43

1.58

1.59

1.61

1.63

1.65

3.10

3.11

3.13

4.08

4.86

4.87

4.89

4.91

5.08

5.11

5.13

5.16

6.52

6.54

S33

13C NMR spectrum of Boc-Leu-Phe-OBn 5b

0102030405060708090100110120130140150160170180190f1 (ppm)

22.0

522

.97

24.7

628

.39

37.9

641

.38

53.2

053

.27

67.3

6

80.1

4

127.

1712

8.64

128.

7012

8.71

129.

4813

5.11

135.

69

155.

61

171.

1817

2.27

S34

1H NMR spectrum of Boc-(R)-Leu-Phe-OBn 5b'

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.10

9.00

2.15

1.97

1.01

0.86

1.00

2.00

0.99

2.03

3.09

4.96

0.87

0.89

1.42

3.05

3.07

3.09

3.10

3.12

3.14

3.15

4.09

4.11

4.13

4.15

4.78

4.79

4.87

4.89

4.90

4.92

5.08

5.11

5.15

5.18

6.61

6.62

S35

13C NMR spectrum of Boc-(R)-Leu-Phe-OBn 5b'

0102030405060708090100110120130140150160170180190f1 (ppm)

21.9

423

.06

24.8

228

.40

37.9

841

.34

53.1

6

67.3

6

80.2

1

127.

2112

8.64

128.

6912

8.73

129.

4213

5.19

135.

71

155.

69

171.

3017

2.31

S36

1H NMR spectrum of Boc-Met-Val-OBn 5c

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.25

9.31

6.34

2.05

0.98

1.03

3.13

1.01

5.00

0.85

0.87

0.91

0.92

1.43

1.95

1.96

2.02

2.04

2.09

2.21

2.55

2.57

2.59

4.30

4.32

4.55

4.56

4.57

4.58

5.11

5.14

5.18

5.21

5.23

6.71

6.73

S37

13C NMR spectrum of Boc-Met-Val-OBn 5c

0102030405060708090100110120130140150160170180190f1 (ppm)

15.2

217

.56

19.1

3

28.4

230

.20

31.1

831

.33

53.2

6

57.2

8

67.1

8

80.2

4

128.

5312

8.59

128.

73

135.

39

171.

5517

1.59

S38

1H NMR spectrum of Boc-Asp(OBn)-Val-OBn 5d

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.02

8.99

1.02

1.02

1.01

1.96

4.00

0.86

0.93

9.61

0.85

0.87

0.90

0.92

1.45

1.68

2.17

2.18

2.19

2.20

2.20

2.68

2.70

2.73

2.74

3.01

3.02

3.05

3.06

4.52

4.53

4.54

4.55

5.12

5.13

5.13

5.17

5.20

5.74

5.76

7.06

7.08

S39

13C NMR spectrum of Boc- Asp(OBn)-Val-OBn 5d

0102030405060708090100110120130140150160170180190f1 (ppm)

17.5

619

.10

28.4

131

.28

36.0

3

50.6

6

57.4

5

67.0

167

.11

80.6

4

128.

3912

8.46

128.

4912

8.55

128.

7213

5.47

135.

50

155.

76

170.

8217

1.43

172.

11

S40

1H NMR spectrum of Boc-Aib-Leu-OBn 5e

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

5.89

8.91

2.77

3.03

2.78

0.98

0.93

2.00

0.81

4.73

0.89

0.90

0.92

1.42

1.45

1.49

1.53

1.55

1.55

1.56

1.57

1.61

1.62

1.63

1.64

1.65

1.66

1.66

1.67

1.67

1.68

1.70

4.60

4.61

4.61

4.62

4.63

4.64

4.65

4.66

4.89

5.10

5.13

5.15

5.18

6.89

S41

13C NMR spectrum of Boc-Aib-Leu-OBn 5e

0102030405060708090100110120130140150160170180f1 (ppm)

21.9

223

.01

24.8

026

.25

28.3

6

41.6

6

50.9

8

56.8

7

67.0

5

128.

3412

8.47

128.

69

135.

58

154.

72

173.

0317

4.49

S42

1H NMR spectrum of TFA.H-Ala-Phe-OBn 6a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.5f1 (ppm)

2.99

0.98

0.98

0.99

0.96

2.00

10.0

3

1.41

1.43

2.98

3.00

3.01

3.03

3.18

3.20

3.22

3.23

3.83

3.85

3.87

3.89

4.74

4.75

4.76

4.78

5.10

5.13

5.14

5.17

S43

13C NMR spectrum of TFA.H-Ala-Phe-OBn 6a

0102030405060708090100110120130140150160170180190f1 (ppm)

17.5

6

38.0

7

49.9

7

55.5

8

68.2

2

128.

0112

9.47

129.

5512

9.58

129.

6113

0.19

136.

9313

7.90

171.

0917

2.35

S44

1H NMR spectrum of TFA.H-Leu-Phe-OBn 6b

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.02

2.90

0.98

0.97

0.96

1.06

2.00

9.97

0.89

0.91

0.92

0.93

0.94

1.58

1.59

1.60

1.61

1.61

1.63

1.65

3.05

3.07

3.19

3.30

3.31

3.31

3.31

3.32

3.81

3.82

3.83

3.84

4.75

4.76

4.77

4.78

4.90

5.08

5.11

5.12

5.15

S45

13C NMR spectrum of TFA.H-Leu-Phe-OBn 6b

0102030405060708090100110120130140150160170180190f1 (ppm)

21.7

723

.22

25.1

7

38.0

6

41.7

1

52.6

855

.67

68.2

2

128.

0112

9.46

129.

5612

9.59

129.

6213

0.18

136.

8813

7.88

170.

9017

2.32

S46

1H NMR spectrum of TFA.H-Met-Val-OBn 6c

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.19

2.13

3.13

1.22

1.98

0.99

1.01

2.00

5.12

2.89

0.98

0.89

0.90

0.90

0.91

1.95

1.96

1.97

1.97

2.01

2.11

2.13

2.46

2.48

2.49

2.50

2.50

2.50

3.35

3.95

3.97

3.98

4.25

4.26

4.26

4.28

5.11

5.14

5.15

5.18

8.20

8.73

8.75

S47

13C NMR spectrum of TFA.H-Met-Val-OBn 6c

0102030405060708090100110120130140150160170180190f1 (ppm)

23.9

527

.51

28.3

7

37.5

139

.18

40.7

1

60.9

1

67.3

1

75.6

8

137.

6213

7.72

137.

97

145.

21

178.

3318

0.34

S48

1H NMR spectrum of TFA.H-Asp(OBn)-Val-OBn 6d

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.07

1.03

2.06

2.04

4.08

10.1

2

2.96

1.00

0.86

0.88

0.90

2.07

2.09

2.10

2.12

2.14

2.15

2.50

2.50

2.50

2.79

2.81

2.85

2.86

3.43

4.27

4.27

4.28

4.29

4.29

4.30

5.07

5.11

5.13

5.14

5.15

5.16

5.18

8.34

8.76

8.78

S49

13C NMR spectrum of TFA.H-Asp(OBn)-Val-OBn 6d

0102030405060708090100110120130140150160170180190f1 (ppm)

17.8

918

.89

29.7

9

35.5

2

48.5

9

57.8

0

66.2

666

.42

128.

2112

8.26

128.

2712

8.47

128.

4913

5.61

135.

67

168.

0016

9.06

170.

66

S50

1H NMR spectrum of TFA.H-Aib-Leu-OBn 6e

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.00

5.74

3.04

0.99

2.00

4.91

2.80

0.96

0.83

0.84

0.87

0.89

0.91

1.30

1.45

1.47

1.57

1.59

1.59

2.08

2.50

2.50

2.50

2.51

4.38

4.39

4.40

4.41

4.42

4.43

4.49

5.09

5.12

5.15

8.23

8.58

8.60

S51

13C NMR spectrum of TFA.H-Aib-Leu-OBn 6e

0102030405060708090100110120130140150160170180190f1 (ppm)

20.8

922

.83

23.3

123

.35

24.3

6

50.8

0

56.3

8

66.1

9

127.

9312

8.20

128.

50

135.

82

171.

8717

2.04

S52

1H NMR spectrum of Boc-Leu-Ala-Phe-OBn 7a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

5.95

2.98

9.87

2.25

1.97

0.98

0.99

1.96

2.00

1.94

2.02

3.01

5.20

0.92

0.93

1.30

1.32

1.42

1.44

1.45

1.46

1.47

1.57

1.59

1.61

1.74

3.09

3.09

3.10

3.11

4.08

4.41

4.43

4.45

4.83

4.85

4.86

4.87

4.88

4.90

5.07

5.10

5.14

5.17

6.58

6.60

6.64

6.66

S53

13C NMR spectrum of Boc-Leu-Ala-Phe-OBn 7a

0102030405060708090100110120130140150160170180190f1 (ppm)

18.2

721

.96

23.1

724

.82

28.4

2

37.8

741

.15

48.9

053

.06

53.4

2

67.4

2

80.3

3

127.

2512

8.67

128.

7112

8.73

129.

4013

5.13

135.

63

155.

87

171.

1517

1.66

172.

54

S54

1H NMR spectrum of Boc-(R)-Leu-Ala-Phe-OBn 7a'

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.60

4.33

10.1

32.

04

2.01

1.00

1.00

2.02

2.06

1.96

2.01

8.74

0.91

0.91

0.92

0.93

1.20

1.24

1.26

1.28

1.30

1.32

1.38

1.42

1.57

1.60

1.62

1.63

3.03

3.04

3.06

3.08

3.09

3.11

3.13

3.14

4.07

4.43

4.45

4.46

4.81

4.82

4.84

4.86

5.06

5.09

5.13

5.16

6.59

6.61

6.67

6.68

S55

13C NMR spectrum of Boc-(R)- Leu-Ala-Phe-OBn 7a'

0102030405060708090100110120130140150160170180f1 (ppm)

18.1

421

.98

23.1

424

.87

28.4

2

37.8

341

.34

48.7

653

.29

53.5

1

67.3

7

80.3

0

127.

2012

8.66

128.

7212

9.42

135.

20

155.

79

171.

1717

1.76

172.

48

S56

1H NMR spectrum of Boc-Gly-Leu-Phe-OBn 7b

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.5f1 (ppm)

5.99

9.13

2.97

1.95

1.96

0.97

1.00

2.00

0.97

1.99

2.03

3.02

5.22

0.84

0.86

0.87

1.25

1.44

1.48

1.49

1.50

1.57

1.58

1.60

3.02

3.04

3.05

3.07

3.10

3.11

3.13

3.68

3.69

3.73

3.74

4.43

4.45

4.47

4.85

4.86

4.88

4.90

5.06

5.09

5.13

5.16

5.24

5.26

5.27

6.70

6.72

6.80

6.82

S57

13C NMR spectrum of Boc-Gly-Leu-Phe-OBn 7b

0102030405060708090100110120130140150160170180190f1 (ppm)

22.1

222

.93

24.6

928

.39

37.8

640

.99

44.2

8

51.5

753

.34

67.3

6

77.3

680

.37

127.

1212

8.62

128.

6512

8.70

129.

4413

5.14

135.

78

156.

09

169.

6117

1.18

171.

65

S58

1H NMR spectrum of Boc-Ser(OBn)-Met-Val-OBn 7c

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.06

9.05

1.97

6.03

1.96

1.00

1.00

0.98

3.02

1.01

1.00

1.00

0.90

0.95

0.89

10.1

2

0.84

0.85

0.88

0.90

1.44

1.77

2.01

2.02

2.04

2.06

2.53

2.54

2.56

3.55

3.56

3.57

3.59

3.89

3.90

4.52

4.53

4.54

4.64

4.66

5.11

5.14

5.18

5.21

5.37

5.39

6.78

6.80

7.21

7.23

S59

13C NMR spectrum of Boc-Ser(OBn)-Met-Val-OBn 7c

0102030405060708090100110120130140150160170180190f1 (ppm)

15.0

117

.68

19.1

7

28.3

930

.02

31.0

7

52.3

5

57.4

5

67.1

969

.86

73.6

2

127.

9312

8.09

128.

5712

8.64

128.

7213

5.41

137.

44

155.

73

170.

4617

0.71

171.

45

S60

1H NMR spectrum of Boc-Trp-Asp(OBn)-Val-OBn 7d

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.15

9.00

1.11

1.01

0.95

1.02

1.00

1.95

1.00

1.11

5.07

1.07

2.09

3.20

11.1

91.

01

0.99

0.78

0.79

0.86

0.87

0.90

1.26

1.41

1.48

1.50

1.80

2.09

2.10

2.12

2.14

2.35

2.36

2.39

2.41

2.89

3.16

3.17

3.19

3.21

3.31

3.32

3.34

4.42

4.43

4.44

4.45

4.74

4.75

4.76

4.77

4.77

4.78

5.05

5.08

5.09

5.11

5.12

5.17

5.20

5.29

7.61

7.63

8.17

S61

13C NMR spectrum of Boc-Trp-Asp(OBn)-Val-OBn 7d

0102030405060708090100110120130140150160170180190f1 (ppm)

17.6

919

.12

28.3

730

.97

35.5

3

49.2

9

55.4

957

.73

66.9

567

.06

80.5

3

111.

3712

2.49

128.

4012

8.49

128.

5312

8.68

128.

70

135.

4713

5.55

136.

33

155.

61

170.

1417

1.37

172.

0117

2.21

S62

1H NMR spectrum of Boc-Pro-Aib-Leu-OBn 7e

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.14

14.5

93.

073.

020.

99

2.01

1.00

1.01

2.00

4.96

0.88

0.89

0.90

0.91

1.41

1.43

1.45

3.39

3.41

3.43

3.45

3.46

3.47

4.12

4.13

4.14

4.48

4.50

5.10

5.13

5.15

5.18

S63

13C NMR spectrum of Boc-Pro-Aib-Leu-OBn 7e

0102030405060708090100110120130140150160170180190f1 (ppm)

22.1

623

.23

24.4

825

.39

25.6

626

.51

28.8

831

.31

32.1

841

.46

47.9

552

.54

57.8

261

.49

67.7

4

81.2

5

129.

2812

9.36

129.

52

137.

30

156.

44

173.

7517

4.53

176.

75

S64

1H NMR spectrum of TFA.H-Leu-Ala-Phe-OBn 8a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

5.31

3.19

2.95

1.98

0.84

0.82

1.02

2.00

9.80

0.91

0.93

0.95

0.96

0.97

0.98

1.29

1.31

1.32

1.43

1.63

1.65

1.66

1.68

1.70

3.03

3.05

3.12

3.30

3.31

3.31

3.31

3.32

3.85

3.85

3.87

4.41

4.43

4.67

4.68

4.69

5.07

5.10

5.12

5.15

S65

13C NMR spectrum of TFA.H-Leu-Ala-Phe-OBn 8a

0102030405060708090100110120130140150160170180190f1 (ppm)

18.2

521

.98

23.1

325

.31

38.2

941

.72

50.1

952

.81

55.3

8

68.0

8

127.

9012

9.40

129.

5012

9.52

130.

3213

6.94

137.

83

172.

5317

2.56

174.

26

S66

1H NMR spectrum of TFA.H-Gly-Leu-Phe-OBn 8b

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.02

1.96

1.02

0.98

0.97

1.93

0.97

1.02

2.00

9.81

0.87

0.89

0.89

0.91

1.46

1.46

1.47

1.48

1.49

1.60

1.62

3.02

3.04

3.12

3.14

3.30

3.31

3.31

3.31

3.32

3.64

3.66

4.43

4.44

4.45

4.46

4.66

4.67

4.68

4.69

4.90

5.07

5.10

5.11

5.14

S67

13C NMR spectrum of TFA.H-Gly-Leu-Phe-OBn 8b

0102030405060708090100110120130140150160170180190f1 (ppm)

21.8

723

.37

25.7

6

38.1

841

.37

42.1

6

52.9

955

.48

68.0

8

127.

8712

9.40

129.

5112

9.56

130.

3013

6.95

137.

99

167.

0517

2.60

174.

48

S68

1H NMR spectrum of TFA.H-Ser(OBn)-Met-Val-OBn 8c

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.03

5.93

1.87

1.99

0.97

1.02

2.95

2.00

10.0

4

2.67

0.97

0.89

0.84

0.85

0.86

0.86

1.77

1.78

1.79

1.81

1.88

1.89

1.90

1.91

1.92

1.92

1.94

1.95

1.99

2.01

2.02

2.04

2.06

2.07

2.09

2.42

2.43

2.44

2.46

2.47

2.47

2.48

2.49

2.50

2.50

2.50

3.65

3.67

3.68

3.69

3.73

3.74

3.76

3.77

4.07

4.08

4.09

4.10

4.18

4.20

4.20

4.22

4.48

4.51

4.52

4.54

4.55

4.56

4.57

4.58

4.59

5.09

5.12

5.13

5.16

8.18

8.37

8.39

8.68

8.70

S69

13C NMR spectrum of TFA.H-Ser(OBn)-Met-Val-OBn 8c

0102030405060708090100110120130140150160170180190f1 (ppm)

14.6

118

.12

18.9

0

29.2

629

.70

32.4

4

51.8

752

.37

57.6

4

65.9

968

.54

72.4

5

127.

6512

8.05

128.

1712

8.26

128.

4613

5.85

137.

58

166.

3517

0.95

171.

15

S70

1H NMR spectrum of TFA.H-Trp-Asp(OBn)-Val-OBn 8d

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.03

1.04

0.99

1.00

1.00

1.02

1.03

1.02

1.33

1.19

1.83

1.07

0.99

1.01

12.1

8

0.99

0.90

0.92

0.94

2.09

2.10

2.12

2.14

2.15

2.17

2.19

2.20

2.77

2.79

2.84

2.85

3.30

3.31

3.31

3.31

3.32

4.15

4.16

4.16

4.33

4.35

4.87

4.88

4.88

4.89

4.90

4.92

4.92

4.93

5.07

5.10

5.12

5.16

5.19

7.66

7.68

S71

13C NMR spectrum of TFA.H-Trp-Asp(OBn)-Val-OBn 8d

-20-100102030405060708090110130150170190210f1 (ppm)

18.4

819

.47

28.8

531

.71

37.0

7

51.2

654

.68

59.5

2

67.8

267

.95

107.

7311

2.63

119.

0512

0.28

122.

9112

5.74

128.

2412

9.34

129.

3812

9.46

129.

5612

9.58

137.

0613

7.21

138.

33

170.

1517

1.57

172.

4317

2.53

S72

1H NMR spectrum of TFA.H-Pro-Aib-Leu-OBn 8e

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.14

5.84

3.00

2.93

0.97

2.01

1.00

0.99

2.00

5.02

1.00

2.00

0.98

0.80

0.82

0.85

0.87

1.35

1.37

1.39

1.48

1.49

1.50

1.51

1.52

1.57

1.59

1.59

1.60

1.61

1.63

1.66

1.66

1.67

1.69

1.82

1.84

1.85

1.87

1.89

1.90

1.92

1.94

1.95

2.23

2.25

2.25

2.26

2.27

2.29

2.49

2.50

2.50

2.50

2.51

3.15

3.16

3.17

3.18

3.20

3.22

3.36

4.16

4.18

4.18

4.20

4.30

4.31

4.32

4.33

4.33

4.34

4.35

4.36

5.06

5.09

5.10

5.13

7.89

7.91

8.54

S73

13C NMR spectrum of TFA.H-Pro-Aib-Leu-OBn 8e

0102030405060708090100110120130140150160170180f1 (ppm)

21.2

322

.87

23.5

024

.12

24.5

225

.03

29.5

4

45.8

6

50.6

1

56.4

659

.07

65.9

0

127.

8912

8.09

128.

43

135.

97

167.

5617

2.38

173.

32

S74

1H NMR spectrum of Boc-Gly-Leu-Ala-Phe-OBn 9a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.15

3.14

9.03

3.28

2.01

1.92

1.98

1.00

2.00

0.95

2.14

4.12

2.55

4.67

0.89

0.90

0.91

0.91

1.25

1.31

1.33

1.43

1.53

1.54

1.56

1.59

3.02

3.03

3.05

3.07

3.10

3.12

3.14

3.15

3.79

3.80

3.82

4.59

4.60

4.67

4.90

4.92

5.06

5.09

5.13

5.16

5.48

S75

13C NMR spectrum of Boc-Gly-Leu-Ala-Phe-OBn 9a

0102030405060708090100110120130140150160170180f1 (ppm)

18.7

122

.23

23.1

224

.80

28.4

5

37.9

542

.05

44.2

648

.80

51.6

153

.50

67.2

9

80.2

0

127.

0412

8.56

128.

6112

8.69

129.

4313

5.24

136.

04

156.

21

169.

4417

1.33

171.

8717

2.21

S76

1H NMR spectrum of Boc-Ala-Gly-Leu-Phe-OBn 9b

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.03

3.09

10.3

52.

23

1.01

0.97

0.99

2.08

1.01

1.00

3.00

3.00

2.07

3.13

4.95

0.85

0.86

0.88

1.25

1.28

1.31

1.33

1.44

1.59

1.63

1.66

3.03

3.05

3.07

3.09

3.13

3.14

3.16

3.80

3.81

4.05

4.07

4.08

4.42

4.43

4.84

4.86

4.88

4.89

5.08

5.09

5.11

5.15

5.18

6.71

6.75

6.77

6.79

S77

13C NMR spectrum of Boc-Ala-Gly-Leu-Phe-OBn 9b

0102030405060708090100110120130140150160170180190f1 (ppm)

11.8

7

18.3

122

.06

22.8

924

.80

28.4

7

37.9

5

43.3

1

49.8

152

.03

53.3

7

67.4

0

80.5

3

127.

0512

8.56

128.

6212

8.71

129.

4913

5.20

155.

78

168.

9817

1.51

171.

7917

3.70

S78

1H NMR spectrum of Boc-Lys(Z)-Ser(OBn)-Met-Val-OBn 9c

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.16

13.1

31.

051.

151.

272.

772.

192.

09

2.05

1.02

2.03

3.99

0.98

4.99

0.72

1.73

15.0

00.

89

0.88

0.89

0.90

0.90

1.25

1.28

1.33

1.35

1.40

1.42

1.43

1.45

1.47

1.49

1.51

1.52

1.87

1.89

1.91

1.93

1.94

2.04

2.16

2.17

2.19

2.21

2.46

2.49

2.51

2.52

3.12

3.14

3.16

3.17

3.57

3.59

3.60

3.61

3.92

3.93

3.94

4.01

4.03

4.46

4.49

4.49

4.50

4.51

4.52

4.55

4.68

4.69

4.70

5.07

5.08

5.09

5.10

5.12

5.13

5.15

5.17

5.20

5.64

5.65

7.01

7.03

7.45

7.47

S79

13C NMR spectrum of Boc-Lys(Z)-Ser(OBn)-Met-Val-OBn 9c

0102030405060708090100110120130140150160170180f1 (ppm)

15.1

518

.07

19.1

322

.35

28.3

228

.40

30.9

831

.08

39.6

1

52.6

853

.98

55.9

357

.70

66.8

969

.03

73.6

2

80.9

0

128.

0412

8.14

128.

2112

8.32

128.

4212

8.60

128.

6913

5.69

137.

33

156.

8215

7.33

170.

0317

1.14

171.

4017

2.61

S80

1H NMR spectrum of Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

5.98

9.04

2.01

1.02

1.02

2.83

0.96

0.95

0.94

0.95

0.95

0.97

0.94

1.88

2.00

0.84

0.94

0.87

5.58

25.3

71.

020.

84

0.81

0.82

0.84

0.86

0.88

0.89

0.91

0.92

1.16

1.21

1.26

1.29

1.34

1.43

1.87

1.88

1.90

1.97

2.10

2.11

2.13

2.15

2.26

2.27

2.29

2.31

2.33

2.47

2.48

3.06

3.08

3.10

3.12

3.28

3.29

3.90

3.92

4.39

4.40

4.41

4.42

4.55

4.56

4.58

4.75

4.76

4.98

5.08

5.11

5.16

5.19

5.60

5.61

6.86

6.86

6.92

6.94

6.99

7.03

7.05

7.08

7.10

7.12

7.13

7.16

7.54

7.56

7.82

S81

13C NMR spectrum of Boc-Gln(Trt)-Trp-Asp(OBn)-Val-OBn 9d

0102030405060708090100110120130140150160170180190f1 (ppm)

17.8

419

.07

27.1

328

.35

28.5

331

.02

33.4

835

.17

49.3

754

.22

54.6

357

.76

66.6

566

.92

70.8

5

80.1

6

109.

5911

1.33

127.

2612

8.14

128.

3512

8.43

128.

6312

8.65

128.

83

135.

6613

6.15

144.

61

156.

12

170.

2517

1.32

171.

5417

1.63

172.

12

S82

1H NMR spectrum of Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.19

15.3

0

3.60

3.29

2.20

1.07

0.82

2.71

4.00

0.70

2.15

2.03

11.2

2

0.65

0.82

0.84

0.85

0.86

1.26

1.31

1.34

1.36

1.41

1.59

1.61

1.85

2.49

2.50

2.50

3.05

3.06

3.07

3.44

3.61

3.61

3.64

4.33

4.34

4.36

5.07

5.12

6.37

6.88

6.91

S83

13C NMR spectrum of Boc-Tyr(OBn)-Pro-Aib-Leu-OBn 9e

102030405060708090100110120130140150160170180190f1 (ppm)

21.7

522

.51

24.0

924

.77

25.9

928

.14

28.1

928

.72

35.4

5

46.9

550

.71

53.9

555

.97

60.0

7

65.8

269

.12

78.0

7

114.

37

127.

5112

7.62

127.

7612

7.84

128.

0112

8.39

129.

8413

0.43

135.

9613

7.22

155.

2315

6.96

170.

5117

1.11

172.

1717

3.96

S84

1H NMR spectrum of Boc-Leu-Ala-Phe-OH 10a

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.5f1 (ppm)

5.98

3.31

8.86

2.07

1.14

1.00

1.00

0.94

1.01

1.03

5.08

0.91

0.93

0.94

1.31

1.32

1.43

1.47

1.49

1.50

1.64

1.70

2.98

3.00

3.02

3.04

3.16

3.17

3.20

3.21

4.06

4.13

4.33

4.35

4.37

4.39

4.60

4.62

4.63

7.17

7.28

S85

13C NMR spectrum of Boc-Leu-Ala-Phe-OH 10a

0102030405060708090100110120130140150160170180190f1 (ppm)

18.3

621

.81

23.5

325

.88

28.7

1

38.3

5

42.0

7

50.0

854

.31

55.1

5

80.5

9

127.

7712

9.41

130.

40

138.

23

157.

91

174.

3517

4.51

175.

33

S86

1H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solution-phase synthesis

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.511.5f1 (ppm)

6.02

3.01

3.06

0.99

1.00

0.98

0.96

0.97

2.01

3.03

0.85

0.86

0.88

1.31

1.32

2.99

3.01

3.02

3.04

3.20

3.21

3.24

3.25

4.20

4.57

4.58

4.91

7.03

7.05

7.12

7.14

7.16

7.17

11.5

0

S87

13C NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solution-phase synthesis

0102030405060708090100110120130140150160170180190f1 (ppm)

18.6

622

.17

23.1

926

.53

39.0

442

.44

52.5

255

.80

56.2

4

129.

8713

0.99

131.

0313

6.61

172.

0917

6.02

178.

94

S88

1H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solid-phase synthesis in DMF

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

6.12

3.07

3.26

0.99

1.06

1.04

1.00

5.39

0.57

Singlets at 8.7, 3.7 and 3.5 ppm correspond to residual DMF. The singlet at 5.2 ppm corresponds to PEG from the ChemMatrix resin.

S89

1H NMR spectrum of TFA.H-Leu-Ala-Phe-OH 11a prepared by solid-phase synthesis in PC

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

5.77

3.42

3.24

0.96

1.00

1.09

1.20

1.02

4.83

2.99

The singlet at 5.2 ppm corresponds to PEG from the ChemMatrix resin.

S90

1H NMR spectrum of HCl.H-Ala-Phe-OBn (in CD3OD) prepared in PC

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

3.01

1.10

1.08

1.00

1.00

2.00

9.74

1.38

1.40

2.95

2.97

2.99

3.01

3.16

3.17

3.19

3.21

3.79

3.81

3.83

3.84

4.71

4.73

4.73

4.75

5.08

5.11

5.12

5.15

S91

HPLC traces of diastereomeric peptides 5a and 5a'

Chromatograms from a reaction carried out at 20 oC

Top Boc-Ala-Phe-OBn 5aMiddle: Boc-(R)-Ala-Phe-OBn 5a'Bottom: 1:1 mixture of 5a and 5a'

S92

Chromatograms from a reaction carried out at 70 oC in a microwave reactor

Top 1:1 mixture of 5a and 5a'Middle: Boc-Ala-Phe-OBn 5a prepared in DMFBottom: Boc-Ala-Phe-OBn 5a prepared in propylene carbonate

S93

HPLC traces of diastereomeric peptides 5b and 5b'

Top Boc-Leu-Phe-OBn 5bMiddle: Boc-(R)-Leu-Phe-OBn 5a'Bottom: 1:1 mixture of 5b and 5b'

S94

HPLC traces of diastereomeric peptides 7a and 7a'

Top Boc-Leu-Ala-Phe-OBn 7aMiddle: Boc-(R)-Leu-Ala-Phe-OBn 7a'Bottom: 1:1 mixture of 7a and 7a'

S95

HPLC-UV-HRMS of Bradykinin

Commercial sample HPLC-UV trace

Commercial sample HRMS of peak at 11.8 minutes

S96

Sample prepared in DMF HPLC-UV trace

Sample prepared in DMF HRMS of peak at 11.8 minutes

S97

Sample prepared in propylene carbonate HPLC-UV trace

Sample prepared in propylene carbonate HRMS of peak at 11.8 minutes

S98

References

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Wang, Y. Wang and M. Kurosu, Org. Lett., 2012, 14, 3372–3375.

S2 H. Rehwinkel and W. Steglich, Synthesis, 1982, 826–827.

S3 D. Hagiwara, H. Miyake, H. Morimoto, M. Murai, T. Fujii and M. Matsuo, J. Med. Chem.,

1992, 35, 2015–2025.

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3689.

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Chem., 2009, 74, 4812–4818.

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1980, 1029–1030.

S8 M. S. Smyth, G. J. Laidig, R. T. Borchardt, B. A. Bunin, C. M. Crews and J. H. Musser,

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Documents

SUPPORTING INFORMATION The Greening of Peptide ...Boc-(R)-Ala-OH (164 mg, 0.87 mmol) and HCl.H-Phe-OBn (250 mg, 0.87 mmol) were coupled according to the general coupling procedure