Research Article Cyanuric Chloride as an Efficient Catalyst for the Synthesis of 2,3 ... · 2019. 7. 31. · 2,3-Unsaturated O -Glycosides by Ferrier Rearrangement XiaojuanYang 1

Research ArticleCyanuric Chloride as an Efficient Catalyst for the Synthesis of23-Unsaturated O-Glycosides by Ferrier Rearrangement

Xiaojuan Yang1 and Na Li2

1 College of Chemistry and Chemical Engineering Xinxiang University Xinxiang Henan 453003 China2 School of Pharmacy Xinxiang Medical University Xinxiang Henan 453003 China

Correspondence should be addressed to Xiaojuan Yang yangxiaojuan2005126com

Received 19 August 2013 Accepted 20 October 2013 Published 19 January 2014

Academic Editors H Miyabe H Pellissier and I Shibata

Copyright copy 2014 X Yang and N Li This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Cyanuric chloride has been found to be an efficient catalyst for the synthesis of 23-unsaturated O-glycosides from the reaction of346-tri-O-acetyl-D-glucal and a wide range of alcohols in dichloromethane at room temperature The experimental procedure issimple and the products are obtained in high yields

1 Introduction

23-Unsaturated O-glycosides play a substantial role in thesynthesis of oligosaccharides [1] uronic acids [2] complexcarbohydrates [3] and various natural products [4 5] More-over the unsaturated part of the sugar ring is amenable to easyfunctionalization such as hydrogenation hydroxylationepoxidation and aminohydroxylation which contribute totheir diversities and complexities One of the most commonprocedures to achieve 23-unsaturated O-glycosides is theacid-catalyzed allyl rearrangement of glucals which was dis-covered by Ferrier and Prasad [6]The Ferrier rearrangementis a reliable procedure for the formation of 23-unsaturated-O-glycosides which has known extensive development overdecades [7]This rearrangement typically occurs by treatmentof glucals and alcohols with Lewis acids such as BF

3sdotEt2O [8]

FeCl3[9] Montmorillonite K-10 [10] I

2[11] InCl

3[12] SiO

2-

Bi(OTf)3[13] ZnCl

2Al2O3[14] or protic acids such as

H2SO4-SiO2[15] H

3PO4[16] H

2SO44 A molecular sieves

[17] CF3SO3H-SiO

2[18] and (S)-camphorsulfonic acid [19]

Er(OTf)3[20 21] as catalyst has also been reported Although

someof thesemethods have beenused for the synthesis of 23-unsaturatedO-glycosides with good to high yields themajor-ity of them suffer at least from one of disadvantages suchas prolonged reaction times low yields harsh reaction con-ditions difficulty in the preparation and moisture sensitivityof the catalysts and high cost and toxicity of the reagents

Therefore there is a scope to develop an alternative methodfor the synthesis of 23-unsaturated O-glycosides

Cyanuric chloride (TCT) is an inexpensive easily avail-able reagent of low toxicity and less corrosiveness than othersimilar reactants and has been widely used in organic reac-tions [22ndash24] but it has not been carefully studied as a catalystin the synthesis of 23-unsaturated O-glycosides until nowIn this paper we wish to report a rapid and highly efficientmethod for the synthesis of 23-unsaturated O-glycosides inthe presence of TCT at room temperature (Scheme 1)

2 Experimental

21 General 1H NMR and 13C NMR spectra were deter-mined on Bruker AV-400 spectrometer at room temperatureusing tetramethylsilane (TMS) as an internal standard cou-pling constants (J) were measured in Hz elemental analyseswere performed by a Vario-III elemental analyzer commer-cially available reagents were used throughout without fur-ther purification unless otherwise stated

22 General Procedure for the Preparation of 3 To a solutionof 346-tri-O-acetyl-D-glucal (272mg 1mmol) in CH

2Cl2

(5mL) were added the corresponding alcohol (12mmol) andTCT (18mg 010mmol) The mixture was stirred at roomtemperature for an appropriate time (Table 2) After comple-tion of the reaction (TLC) the reaction mixture was treated

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 307895 6 pageshttpdxdoiorg1011552014307895

2 The Scientific World Journal

O

OAc

AcOAcO

AcOAcO

+

ROH

OROTCT

(1) (2) (3)

N N

N ClCl

Cl

CH2Cl2 rt

Scheme 1 Synthesis of 23-unsaturated O-glycosides

with 10mL water and extracted with CH2Cl2(3 times 10mL)

The combined organics were dried over anhydrous Na2SO4

The solvent was removed under vacuum All the pro-ducts were purified by silica gel column chromatography(hexaneethyl acetate = 91) The structures of products wereidentified through comparison of these spectra data withthose in the known literatures [8ndash19] Spectral data for sel-ected compounds are as follows

23 Spectral Data of Some Selected Compounds n-Butyl 46-di-O-acetyl-23-dideoxy-120572-D-erythro-hex-2-enopyranoside(3c) 1H NMR (400MHz CDCl

3) 120575 580ndash565 (m 2H) 518

(dd J = 12 96Hz 1H) 490 (s 1H) 406 (dd J = 56 124Hz1H) 42 (dd J = 24 12Hz 1H) 398ndash394 (m 1H) 366ndash335(m 2H) 195 (s 3H) 194 (s 3H) 147ndash123 (m 4H) 081 (t3H) 13C NMR (100Hz CDCl

3) 120575 1705 1701 1290 1281

936 689 670 656 629 318 208 207 189 138 AnalCalcd for C

14H22O6 C 5873 H 774 Found C 5865 H 769

Benzyl 46-di-O-acetyl-23-dideoxy-120572-D-erythro-hex-2-enopyranoside (3l) 1HNMR (400MHz CDCl

3) 120575 733ndash725

(m 5H) 593ndash583 (m 2H) 529 (dd J = 16 28Hz 1H) 512(s 1H) 482 (d J = 116Hz 1H) 464ndash455 (m 1H) 432ndash408(m 3H) 207 (s 3H) 205 (s 3H) 13CNMR (100Hz CDCl

3)

120575 1705 1701 1374 1295 1283 1280 1278 1277 929 706672 649 630 208 206 Anal Calcd for C

17H20O6 C 6374

H 629 Found C 6388 H 620Cyclohex-2-enyl 46-di-O-acetyl-23-dideoxy-120572-D-eryth-

ro-hex-2-enopyranoside (3j) 1HNMR (400MHz CDCl3) 120575

587ndash575 (m 4H) 530 (d J = 88Hz 1H) 520 (d J = 180Hz1H) 427ndash414 (m 4H) 209 (s 3H) 208 (s 3H) 203ndash193(m 3H) 184ndash170 (m 2H) 156 (m 1H) 13C NMR (100HzCDCl

3) 120575 1707 1703 1316 1288 1286 1284 1283 938

729 670 656 629 299 248 212 198 Anal Calcd forC15H24O6 C 5998 H 805 Found C 6002 H 802

Pregnenolonyl 46-di-O-acetyl-23-dideoxy-120572-D-eryth-ro-hex-2-enopyranoside (3o) 1HNMR(400MHzCDCl

3)120575

586 (d J = 100Hz 1H) 575 (d J = 100Hz 1H) 531 (s 1H)524 (d J = 100Hz 1H) 513 (s 1H) 420ndash355 (m 4H) 252 (tJ = 80Hz 1H) 238ndash214 (m 3H) 211 (s 3H) 206 (s 3H)205 (s 3H) 202 (d J = 95Hz 1H) 199ndash142 (m 11H) 123ndash111 (m 2H) 106ndash096 (m 5H) 062 (s 3H) 13C NMR(100Hz CDCl

3) 120575 2089 1708 1703 1405 1287 1282 1213

930 782 670 655 637 632 564 500 441 405 383 373362 318 317 314 279 243 228 212 210 208 195 135Anal Calcd for C

31H44O7 C 7043 H 839 Found C 7029

H 827

Table 1 Reaction conditions optimisation for the synthesis of 3a

Entry Catalystmmol Solvent Timemin Yield1 0 CH2Cl2 120 Trace2 005 CH2Cl2 60 793 010 CH2Cl2 30 904 015 CH2Cl2 30 895 020 CH2Cl2 30 906 010 CH3CN 30 827 010 Acetone 30 808 010 THF 30 699 010 Ethyl ether 60 42

3 Results and Discussion

In a typical reaction procedure 23-unsaturatedO-glycosides3 were prepared from the reaction of 346-tri-O-acetyl-D-glucal 1 and alcohols 2 in CH

2Cl2at room temperature in the

presence of TCT as catalyst (Scheme 1) Since in this new kindof methodology there is a great challenge to find new cata-lysts able to perform the reactions with high activities weconsidered TCT as a potential promoter due to its good fea-tures for such a transformation During our investigation wefirstly chose the reaction of 346-tri-O-acetyl-D-glucal(1mmol) andmethanol (12mmol) asmodel reactants and ex-amined the effect of the different amounts of TCT (Table 1)When above model reactants were conducted in CH

2Cl2

(5mL) in the presence of 0 005 010 015 and 020mmol ofTCT separately the best result was obtained using 010mmolof catalyst (yield = 90) Using lower amounts of catalystresulted in lower yields while higher amounts of catalyst didnot affect the reaction times and yields (Table 1 entries 2ndash5) In the absence of catalyst the product was not formed(Table 1 entry 1) In order to evaluate the effect of the solventthe reaction of 346-tri-O-acetyl-D-glucal and methanol inthe presence of TCT was performed in various solvents suchas CH

2Cl2 CH3CN acetone THF and ethyl ether in which

the best result was obtained inCH2Cl2(Table 1 entry 3) thus

we chose it as the solvent for all further reactions (Table 1entries 6ndash9)

Under the optimum conditions a wide range of alcoholsincluding primary secondary and allylic alcohols reactedwith acetylated glucal according to Scheme 1 using 10mol of TCT at room temperature to give the corresponding 23-unsaturated O-glycosides in good to excellent yields and invery short reaction time with 120572-anomer as a major product(Table 2)

Encouraged by these results we next explored the scopeof this methodology for the synthesis of pseudoglycals con-nected to various biologically important natural products(Table 2 entries 15ndash17) Under our catalytic conditions preg-nenolone L-menthol and borneol pseudoglycosides wereobtained in 86 88 and 85 yields respectively withexclusive 120572-anomeric selectivity

The formation of products can be explained as followsinitially TCT reacts with the adventitious moisture to form3mol of HCl and cyanuric acid (removable by water wash-ing) as a byproduct The in situ generated HCl assists the

The Scientific World Journal 3

Table 2 Preparation of 23-unsaturated O-glycosides

Entry Alcohols Products Timemin Yield 120572120573a

1 MeOH

3a

O OMeAcO

AcO 30 90 7 1

2 EtOH

3b

O OEtAcO

AcO 30 91 10 1

3 OH

3c

O O

AcO

AcO

45 84 8 1

4 OH

3d

O O

AcO

AcO30 89 8 1

5 OH

3e

O O

AcO

AcO30 93 120572

6 OH

3f

O O

AcO

AcO45 89 120572

7 OH

3g

O OAcO

AcO45 90 120572

8 O OH

3h

O O O

AcO

AcO

30 88 8 1

9 Cl OHCl

Cl

3i

O OCl

ClCl

AcO

AcO45 85 11 1

10OH

3j

O OAcO

AcO45 94 11 1


Table 2 Continued


11OH

3k

O O

AcO

AcO45 91 10 1

12OH OAcO

AcO

O

3l

60 88 9 1

13 OH

OMe

AcO

AcO

OMe

O O

3m

60 87 9 1

14OH

3n

O OAcO

AcO60 86 120572

15 H

H H

O

HO

O

H

H H

O

OAcO

AcO

3o

60 86 120572

16OH

3p

OOAcO

AcO

45 88 120572

17

OH

OAcO

AcO

O

3q

45 85 120572

aThe 120572120573 ratio was determined from the anomeric proton ratio in the 1H NMR spectra


N

N

N

Cl

Cl ClHCl N

N

N

OH

OHHO

O

OAc

AcO

AcO AcO

AcO AcO

AcO

O ROH ORO

I(1)

(2)

(3)

H2O+ +

+

Scheme 2 Plausible mechanism for the formation of 23-unsaturated O-glycosides

formation of the intermediate cyclic allylic oxocarbenium ionI from 346-tri-O-acetyl-D-glucal which was originally pro-posed by Ferrier Then alcohol is added to the intermediateI in a quasiaxial fashion preferentially to provide the product23-unsaturated O-glycosides 3 having major 120572-selectivity asshown in Scheme 2

4 Conclusion

In conclusion we have developed a mild eco-friendly ap-proach for the synthesis of 23-unsaturated O-glycosidesusing a catalytic quantity of TCTThemain advantages of thismethod include good120572-selectivity the use of inexpensive cat-alyst and environmentally benign character We believe thatthe methodology reported here is synthetically quite attrac-tive andwould spur on further interest toward the synthesis ofcomplex glycosides

Conflict of Interests

The authors have declared that no conflict of interest exists

Acknowledgment

The authors are pleased to acknowledge the financial supportfrom Xinxiang College

References

[1] V D Bussolo Y-J Kim and D Y Gin ldquoDirect oxidative glyco-sylations with glycal donorsrdquo Journal of the American ChemicalSociety vol 120 no 51 pp 13515ndash13516 1998

[2] R R Schmidt and R Angerbauer ldquoA short synthesis of racemicuronic acids and 23-anhydrouronic acidsrdquo Carbohydrate Re-search vol 89 no 1 pp 159ndash162 1981

[3] R R Schmidt and R Angerbauer ldquoSimple de-novo synthesis ofreactive pseudoglycals (hex-2-enopyranosides)-stereospecific120572-glycoside couplingrdquo Angewandte Chemie vol 16 no 11 pp783ndash784 1977

[4] A G Tolstikov and G A Tolstikov ldquoGlycals in enantiospecificsynthesisrdquoRussian Chemical Reviews vol 62 no 6 pp 579ndash6011993

[5] B Fraser-Reid ldquoSome progeny of 23-unsaturated sugarsmdashtheylittle resemble grandfather glucose ten years laterrdquo Accounts ofChemical Research vol 18 no 11 pp 347ndash354 1985

[6] R J Ferrier andN Prasad ldquoUnsaturated carbohydrates Part IXSynthesis of 23-dideoxy-120572-D-erythro-hex-2-enopyranosidesfrom tri-O-acetyl-D-glucalrdquo Journal of the Chemical Society Cvol 1969 no 4 pp 570ndash575 1969

[7] P Chen and P Xiang ldquoRecent advances in the Ferrier-type rear-rangement reactions and their applications in the complex bio-active moleculesrdquo Chinese Journal of Organic Chemistry vol 31no 8 pp 1195ndash1201 2011

[8] E Wieczorek and J Thiem ldquoPreparation of modified glycosylglycerol derivatives by glycal rearrangementrdquo CarbohydrateResearch vol 307 no 3-4 pp 263ndash270 1998

[9] R D TilveM V Alexander A C Khandekar S D Samant andV R Kanetkar ldquoSynthesis of 23-unsaturated glycopyranosidesby Ferrier rearrangement in FeCl

3based ionic liquidrdquo Journal of

Molecular Catalysis A vol 223 no 1-2 pp 237ndash240 2004[10] K Toshima N Miyamoto G Matsuo M Nakata and S Mat-

sumura ldquoEnvironmentally compatible C-glycosidation of gly-cals using montmorillonite K-10rdquo Chemical Communicationsno 11 pp 1379ndash1380 1996

[11] M Koreeda T A Houston B K Shull E Klemke and R JTuinman ldquoIodine-catalyzed Ferrier reaction 1 A mild andhighly versatile glycosylation of hydroxyl and phenolic groupsrdquoSynlett vol 1995 no 1 pp 90ndash92 1995

[12] B S Babu and K K Balasubramanian ldquoIndium trichloride cat-alyzed glycosidation An expeditious synthesis of 23-unsatu-rated glycopyranosidesrdquo Tetrahedron Letters vol 41 no 8 pp1271ndash1274 2000

[13] J L Babu A Khare and Y D Vankar ldquoBi(OTf)3and SiO

2-

Bi(OTf)3as effective catalysts for the Ferrier rearrangementrdquo

Molecules vol 10 no 8 pp 884ndash892 2005[14] B K Gorityala R Lorpitthaya Y Bai and X-W Liu ldquoZnCl

2

alumina impregnation catalyzed Ferrier rearrangement an ex-pedient synthesis of pseudoglycosidesrdquo Tetrahedron vol 65 no29-30 pp 5844ndash5848 2009

[15] J F Zhou X ChenQ BWang et al ldquoH2SO4ndashSiO2 highly effic-

ient and novel catalyst for the Ferrier-type glycosylationrdquo Chi-nese Chemical Letters vol 21 no 8 pp 922ndash926 2010

[16] B K Gorityala S Cai R Lorpitthaya J Ma K K PasunootiandX-W Liu ldquoA convenient synthesis of pseudoglycosides via aFerrier-type rearrangement using metal-free H

3PO4catalystrdquo

Tetrahedron Letters vol 50 no 6 pp 676ndash679 2009[17] J Zhou B Zhang G Yang et al ldquoA facile H

2SO44 A molecular

sieves catalyzed synthesis of 23-unsaturated O-glycosides via


Ferrier-type rearrangementrdquo Synlett vol 2010 no 6 pp 893ndash896 2010

[18] P Chen and S Wang ldquoCF3SO3HndashSiO

2as catalyst for Ferrier

rearrangement an efficient procedure for the synthesis of pseu-doglycosidesrdquo Tetrahedron vol 69 no 2 pp 583ndash588 2013

[19] B K Gorityala S Cai J Ma and X-W Liu ldquo(S)-Camphorsul-fonic acid catalyzed highly stereoselective synthesis of pseudo-glycosidesrdquo Bioorganic amp Medicinal Chemistry Letters vol 19no 11 pp 3093ndash3095 2009

[20] A Procopio R Dalpozzo A De Nino M Nardi M Oliverioand B Russo ldquoEr(OTf)

3as a valuable catalyst in a short syn-

thesis of 2101584031015840-dideoxy pyranosyl nucleosides via Ferrier rear-rangementrdquo Synthesis vol 2006 no 15 pp 2608ndash2612 2006

[21] A Procopio R Dalpozzo A De Nino et al ldquoA facile Er(OTf)3-

catalyzed synthesis of 23-unsaturated O- and S-glycosidesrdquoCarbohydrate Research vol 342 no 14 pp 2125ndash2131 2007

[22] G V M Sharma J J Reddy P S Lakshmi and P R KrishnaldquoA versatile and practical synthesis of bis(indolyl)methanesbis(indolyl) glycoconjugates catalyzed by trichloro-135-tria-zinerdquo Tetrahedron Letters vol 45 no 41 pp 7729ndash7732 2004

[23] L Wu X Yang X Wang and F Yan ldquoCyanuric chloride-cat-alyzed synthesis of N-sulfonyl iminesrdquo Journal of Sulfur Chem-istry vol 31 no 6 pp 509ndash513 2010

[24] M A Bigdeli M M Heravi and G H Mahdavinia ldquoWet cya-nuric chloride catalyzed simple and efficient synthesis of 14-arylor alkyl-14-H-dibenzo[aj]xanthenesrdquo Catalysis Communica-tions vol 8 no 11 pp 1595ndash1598 2007

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


O

OAc

AcOAcO

AcOAcO

+

ROH

OROTCT

(1) (2) (3)

N N

N ClCl

Cl

CH2Cl2 rt

Scheme 1 Synthesis of 23-unsaturated O-glycosides

with 10mL water and extracted with CH2Cl2(3 times 10mL)

The combined organics were dried over anhydrous Na2SO4

The solvent was removed under vacuum All the pro-ducts were purified by silica gel column chromatography(hexaneethyl acetate = 91) The structures of products wereidentified through comparison of these spectra data withthose in the known literatures [8ndash19] Spectral data for sel-ected compounds are as follows

23 Spectral Data of Some Selected Compounds n-Butyl 46-di-O-acetyl-23-dideoxy-120572-D-erythro-hex-2-enopyranoside(3c) 1H NMR (400MHz CDCl

3) 120575 580ndash565 (m 2H) 518

(dd J = 12 96Hz 1H) 490 (s 1H) 406 (dd J = 56 124Hz1H) 42 (dd J = 24 12Hz 1H) 398ndash394 (m 1H) 366ndash335(m 2H) 195 (s 3H) 194 (s 3H) 147ndash123 (m 4H) 081 (t3H) 13C NMR (100Hz CDCl

3) 120575 1705 1701 1290 1281

936 689 670 656 629 318 208 207 189 138 AnalCalcd for C

14H22O6 C 5873 H 774 Found C 5865 H 769

Benzyl 46-di-O-acetyl-23-dideoxy-120572-D-erythro-hex-2-enopyranoside (3l) 1HNMR (400MHz CDCl

3) 120575 733ndash725

(m 5H) 593ndash583 (m 2H) 529 (dd J = 16 28Hz 1H) 512(s 1H) 482 (d J = 116Hz 1H) 464ndash455 (m 1H) 432ndash408(m 3H) 207 (s 3H) 205 (s 3H) 13CNMR (100Hz CDCl

3)

120575 1705 1701 1374 1295 1283 1280 1278 1277 929 706672 649 630 208 206 Anal Calcd for C

17H20O6 C 6374

H 629 Found C 6388 H 620Cyclohex-2-enyl 46-di-O-acetyl-23-dideoxy-120572-D-eryth-

ro-hex-2-enopyranoside (3j) 1HNMR (400MHz CDCl3) 120575

587ndash575 (m 4H) 530 (d J = 88Hz 1H) 520 (d J = 180Hz1H) 427ndash414 (m 4H) 209 (s 3H) 208 (s 3H) 203ndash193(m 3H) 184ndash170 (m 2H) 156 (m 1H) 13C NMR (100HzCDCl

3) 120575 1707 1703 1316 1288 1286 1284 1283 938

729 670 656 629 299 248 212 198 Anal Calcd forC15H24O6 C 5998 H 805 Found C 6002 H 802

Pregnenolonyl 46-di-O-acetyl-23-dideoxy-120572-D-eryth-ro-hex-2-enopyranoside (3o) 1HNMR(400MHzCDCl

3)120575

586 (d J = 100Hz 1H) 575 (d J = 100Hz 1H) 531 (s 1H)524 (d J = 100Hz 1H) 513 (s 1H) 420ndash355 (m 4H) 252 (tJ = 80Hz 1H) 238ndash214 (m 3H) 211 (s 3H) 206 (s 3H)205 (s 3H) 202 (d J = 95Hz 1H) 199ndash142 (m 11H) 123ndash111 (m 2H) 106ndash096 (m 5H) 062 (s 3H) 13C NMR(100Hz CDCl

3) 120575 2089 1708 1703 1405 1287 1282 1213

930 782 670 655 637 632 564 500 441 405 383 373362 318 317 314 279 243 228 212 210 208 195 135Anal Calcd for C

31H44O7 C 7043 H 839 Found C 7029

H 827

Table 1 Reaction conditions optimisation for the synthesis of 3a

Entry Catalystmmol Solvent Timemin Yield1 0 CH2Cl2 120 Trace2 005 CH2Cl2 60 793 010 CH2Cl2 30 904 015 CH2Cl2 30 895 020 CH2Cl2 30 906 010 CH3CN 30 827 010 Acetone 30 808 010 THF 30 699 010 Ethyl ether 60 42

3 Results and Discussion

In a typical reaction procedure 23-unsaturatedO-glycosides3 were prepared from the reaction of 346-tri-O-acetyl-D-glucal 1 and alcohols 2 in CH

2Cl2at room temperature in the

presence of TCT as catalyst (Scheme 1) Since in this new kindof methodology there is a great challenge to find new cata-lysts able to perform the reactions with high activities weconsidered TCT as a potential promoter due to its good fea-tures for such a transformation During our investigation wefirstly chose the reaction of 346-tri-O-acetyl-D-glucal(1mmol) andmethanol (12mmol) asmodel reactants and ex-amined the effect of the different amounts of TCT (Table 1)When above model reactants were conducted in CH

2Cl2

(5mL) in the presence of 0 005 010 015 and 020mmol ofTCT separately the best result was obtained using 010mmolof catalyst (yield = 90) Using lower amounts of catalystresulted in lower yields while higher amounts of catalyst didnot affect the reaction times and yields (Table 1 entries 2ndash5) In the absence of catalyst the product was not formed(Table 1 entry 1) In order to evaluate the effect of the solventthe reaction of 346-tri-O-acetyl-D-glucal and methanol inthe presence of TCT was performed in various solvents suchas CH

2Cl2 CH3CN acetone THF and ethyl ether in which

the best result was obtained inCH2Cl2(Table 1 entry 3) thus

we chose it as the solvent for all further reactions (Table 1entries 6ndash9)

Under the optimum conditions a wide range of alcoholsincluding primary secondary and allylic alcohols reactedwith acetylated glucal according to Scheme 1 using 10mol of TCT at room temperature to give the corresponding 23-unsaturated O-glycosides in good to excellent yields and invery short reaction time with 120572-anomer as a major product(Table 2)

Encouraged by these results we next explored the scopeof this methodology for the synthesis of pseudoglycals con-nected to various biologically important natural products(Table 2 entries 15ndash17) Under our catalytic conditions preg-nenolone L-menthol and borneol pseudoglycosides wereobtained in 86 88 and 85 yields respectively withexclusive 120572-anomeric selectivity

The formation of products can be explained as followsinitially TCT reacts with the adventitious moisture to form3mol of HCl and cyanuric acid (removable by water wash-ing) as a byproduct The in situ generated HCl assists the




1 MeOH

3a

O OMeAcO

AcO 30 90 7 1

2 EtOH

3b

O OEtAcO

AcO 30 91 10 1

3 OH

3c

O O

AcO

AcO

45 84 8 1

4 OH

3d

O O

AcO

AcO30 89 8 1

5 OH

3e

O O

AcO

AcO30 93 120572

6 OH

3f

O O

AcO

AcO45 89 120572

7 OH

3g

O OAcO

AcO45 90 120572

8 O OH

3h

O O O

AcO

AcO

30 88 8 1

9 Cl OHCl

Cl

3i

O OCl

ClCl

AcO

AcO45 85 11 1

10OH

3j

O OAcO

AcO45 94 11 1


Table 2 Continued


11OH

3k

O O

AcO

AcO45 91 10 1

12OH OAcO

AcO

O

3l

60 88 9 1

13 OH

OMe

AcO

AcO

OMe

O O

3m

60 87 9 1

14OH

3n

O OAcO

AcO60 86 120572

15 H

H H

O

HO

O

H

H H

O

OAcO

AcO

3o

60 86 120572

16OH

3p

OOAcO

AcO

45 88 120572

17

OH

OAcO

AcO

O

3q

45 85 120572



N

N

N

Cl

Cl ClHCl N

N

N

OH

OHHO

O

OAc

AcO

AcO AcO

AcO AcO

AcO

O ROH ORO

I(1)

(2)

(3)

H2O+ +

+



4 Conclusion




Acknowledgment


References
















2-



2





3PO4catalystrdquo


2SO44 A molecular

























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




1 MeOH

3a

O OMeAcO

AcO 30 90 7 1

2 EtOH

3b

O OEtAcO

AcO 30 91 10 1

3 OH

3c

O O

AcO

AcO

45 84 8 1

4 OH

3d

O O

AcO

AcO30 89 8 1

5 OH

3e

O O

AcO

AcO30 93 120572

6 OH

3f

O O

AcO

AcO45 89 120572

7 OH

3g

O OAcO

AcO45 90 120572

8 O OH

3h

O O O

AcO

AcO

30 88 8 1

9 Cl OHCl

Cl

3i

O OCl

ClCl

AcO

AcO45 85 11 1

10OH

3j

O OAcO

AcO45 94 11 1


Table 2 Continued


11OH

3k

O O

AcO

AcO45 91 10 1

12OH OAcO

AcO

O

3l

60 88 9 1

13 OH

OMe

AcO

AcO

OMe

O O

3m

60 87 9 1

14OH

3n

O OAcO

AcO60 86 120572

15 H

H H

O

HO

O

H

H H

O

OAcO

AcO

3o

60 86 120572

16OH

3p

OOAcO

AcO

45 88 120572

17

OH

OAcO

AcO

O

3q

45 85 120572



N

N

N

Cl

Cl ClHCl N

N

N

OH

OHHO

O

OAc

AcO

AcO AcO

AcO AcO

AcO

O ROH ORO

I(1)

(2)

(3)

H2O+ +

+



4 Conclusion




Acknowledgment


References
















2-



2





3PO4catalystrdquo


2SO44 A molecular

























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Table 2 Continued


11OH

3k

O O

AcO

AcO45 91 10 1

12OH OAcO

AcO

O

3l

60 88 9 1

13 OH

OMe

AcO

AcO

OMe

O O

3m

60 87 9 1

14OH

3n

O OAcO

AcO60 86 120572

15 H

H H

O

HO

O

H

H H

O

OAcO

AcO

3o

60 86 120572

16OH

3p

OOAcO

AcO

45 88 120572

17

OH

OAcO

AcO

O

3q

45 85 120572



N

N

N

Cl

Cl ClHCl N

N

N

OH

OHHO

O

OAc

AcO

AcO AcO

AcO AcO

AcO

O ROH ORO

I(1)

(2)

(3)

H2O+ +

+



4 Conclusion




Acknowledgment


References
















2-



2





3PO4catalystrdquo


2SO44 A molecular

























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


N

N

N

Cl

Cl ClHCl N

N

N

OH

OHHO

O

OAc

AcO

AcO AcO

AcO AcO

AcO

O ROH ORO

I(1)

(2)

(3)

H2O+ +

+



4 Conclusion




Acknowledgment


References
















2-



2





3PO4catalystrdquo


2SO44 A molecular

























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of
























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Cyanuric Chloride as an Efficient Catalyst for the Synthesis of 2,3 ... · 2019. 7. 31. · 2,3-Unsaturated O -Glycosides by Ferrier Rearrangement XiaojuanYang 1