First Exam CHEM 256 – Organic Chemistry II Prof. Bastin ... · First Exam CHEM 256 – Organic Chemistry II Prof. Bastin Spring 2013 Name _____ Provide clear, concise answers using

First Exam CHEM 256 – Organic Chemistry II

Prof. Bastin Spring 2013

Name ___________________________ Provide clear, concise answers using unambiquous, carefully drawn structures (where appropriate) for all of the questions. Good luck and enjoy!

1) _______/10 pts 2) _______/10 pts

3) _______/12 pts

4) _______/12 pts Total: ________/100 pts 5) _______/8 pts

6) _______/20 pts

7) _______/10 pts 8) _______/8 pts 9) _______/10 pts

Bastin – Exam #1 Chem 256 - Spring 2013

2

1) (10 pts) Provide structures for the following compounds.

(a) 2,3-diethoxybutane (b) sec-butyl alcohol

(c) cis-2-ethylcyclobutanol (d) (2S, 3S)-3-ethoxy-2-pentanol (e) butyl hexyl ether


3

2) (10 pts) Provide either common or IUPAC names for the following compounds. (a) (b)

(c) (d)

(e)

H OH

O

OCH2CH3

OH

Cl OH

O

OH


4

3) (12 pts) Draw the product(s), if any, of the following reactions. Indicate stereochemistry where relevant.

a)

b)

c)

d)

e)

f)

OH polymer-supported CrO3Toluene

OH 1)TsCl2) NaI

O

CH3

NaSHH2O

OH

OH

HIO4

OH2 H2SO4Δ

1) Br2/H2O2) NaOH


5

4) (12 pts) Provide the reagents needed to bring about the following transformations.

a)

b)

(c)

(d)

(e)

(f)

OOH

H3CH2C CH3

H3CH2CH2COH

H3CH2C CH3

H3CH2CH2COH

O

OOH

OCH2CH3

OHH

O

O

Br

Br

+

OH Br


6

5) (8 pts) Assume you are carrying out the oxidation shown below. How could you use IR spectroscopy to determine when the reaction is complete? Provide as many different analyses you can think of.

6) (20 pts) Devise (on the following blank page) a synthesis for the following

transformations using any reagents that we have discussed. If you need more space, please ask and I will provide you with an additional sheet of paper. For FULL credit be sure to show the retrosynthetic analysis AND the complete synthesis.

a)

b)

H

O

OH

O

[O]

O

OH

from

Cl

and

These molecules are your only source of carbon

from OH

This molecule is your only source of carbon


7


8

7) (10 pts) For each of the following IR spectra (a-e) there is a choice of three possible types of compounds. For each spectrum, choose the most appropriate class of compound. Explain your reasoning by noting the presence or absence of characteristic bands in the spectrum.

a) alcohol, carboxylic acid, or phenol

b) aldehyde, ester, or ketone

c) 1-alkyne, symmetrical internal alkyne, or nitrile

PR0BLEM 15.34 (C0lrTrr{UED).l Microns (F)

22 2.12.A2.A 3 3,5 44,5 5 5.5 0 7 I 910 11 12131a15t0lEm225

AlcoholCarboryllc acldPhenol

a 2.6 2.8 3 3.5 a 4.5

2 AldehydeEsterKetone2.2 2,4 2,4 2,4 3 3.5 4 4.5

Microns 0r)5 5.5 6 7 8 I10 t l 1?!3 l4t5r6.r l t | i

Microns 0r)5 5.6 6 7 6 I t0 1t 12t14r5r! 'a

so

o

EE 1psoEF2@ ru@1@1@r@iA1@

Wavenumb€r (cml )

Mims0)3.5 . .5 5 55 6 7 S 910

& m m 20 rum1&10101rurm & Gwsvonumber (crr1)

ao

c

E

IF2

Eo6

c

sF

oo

o

so

E6qt

21 2.4 2.E 3 11 12 13 1a 1510 11 82 25

s re & @&1@1@ro1&1@Wavsnumber (cm-l)

Microns (p)5678910111213!415r8

@ re m mmrsrorolrur@Wavmumb€r (cml)

3 l-AlkyneSymmetrlcal dlsubstltuted alkyneGyanide Mtcrons (r)22 2t 2.e2.4 3 3.5 I 1.5 5 5.5 6 7 8 I 10

4-

silf*-\ f-T-\rrn n*,d1lt11 12 13 ta 15.a r

FogsE0po.Ee4

8a

EoEF

Microns 0422 2.4232.6 3 3.5 44.5 5 5.5 6 7 8 9r0 f i 12131a1514r8n25

w 2m 2mm1&1m1&1mtmWavenumbor (cml)

Micmns (p)22 2.42.62.8 3 3-5 a4.5 5 5.56 7 E 910 11 12131ar5r61E626

@ @ m 2m ro@rmlm101&1@Wavonumbs (cr1)

4 Primary amidePrimary amineNitro compound

1 2.6 2.8 g 3.3 a a.!Microns (F)

5.5 6 7 a 910 11 12 13 r . r l t I

@oo

EF

*-v*2& 2mro1&tmr@!ru1s

Wavonumbsr (cm-1)

PR0BIEM 15.35 For each of the following lR spectra (1-5)there is a choice of three possible types of compounds. Foreach spectrum, choose the most appropriate class of com-pound. Explain your reasoning by noting the presence or ab-sence of characteristic bands in the soectrum.

@ @ ru 2m m@1m1@1@1m1@Wav€numbs (cr1)

5 AnhydrideGarboxylic acidEster Microns (d2.2 2.42.82.5 3 3.5 44.5 5 5.5 6 7 I 910 11 12131. ' ! ! .

@ @ ru 2m ru@rmr&tolru1mWav6numb6r (cm1)

0.0q601 >0.2803Ao.r P0.5 60.6 0

1.02.0

rf1ms&70@s{s10

Wav€number (crn-l)


22 2.12.A2.A 3 3,5 44,5 5 5.5 0 7 I 910 11 12131a15t0lEm225


a 2.6 2.8 3 3.5 a 4.5




so

o


Wavenumb€r (cml )

Mims0)3.5 . .5 5 55 6 7 S 910


ao

c

E

IF2

Eo6

c

sF

oo

o

so

E6qt

21 2.4 2.E 3 11 12 13 1a 1510 11 82 25


Microns (p)5678910111213!415r8



4-


FogsE0po.Ee4

8a

EoEF

Microns 0422 2.4232.6 3 3.5 44.5 5 5.5 6 7 8 9r0 f i 12131a1514r8n25


Micmns (p)22 2.42.62.8 3 3-5 a4.5 5 5.56 7 E 910 11 12131ar5r61E626



1 2.6 2.8 g 3.3 a a.!Microns (F)

5.5 6 7 a 910 11 12 13 r . r l t I

@oo

EF


Wavonumbsr (cm-1)





0.0q601 >0.2803Ao.r P0.5 60.6 0

1.02.0

rf1ms&70@s{s10



22 2.12.A2.A 3 3,5 44,5 5 5.5 0 7 I 910 11 12131a15t0lEm225


a 2.6 2.8 3 3.5 a 4.5




so

o


Wavenumb€r (cml )

Mims0)3.5 . .5 5 55 6 7 S 910


ao

c

E

IF2

Eo6

c

sF

oo

o

so

E6qt

21 2.4 2.E 3 11 12 13 1a 1510 11 82 25


Microns (p)5678910111213!415r8



4-


FogsE0po.Ee4

8a

EoEF

Microns 0422 2.4232.6 3 3.5 44.5 5 5.5 6 7 8 9r0 f i 12131a1514r8n25


Micmns (p)22 2.42.62.8 3 3-5 a4.5 5 5.56 7 E 910 11 12131ar5r61E626



1 2.6 2.8 g 3.3 a a.!Microns (F)

5.5 6 7 a 910 11 12 13 r . r l t I

@oo

EF


Wavonumbsr (cm-1)





0.0q601 >0.2803Ao.r P0.5 60.6 0

1.02.0

rf1ms&70@s{s10



9

d) primary amide, primary amine, or nitro compound

e) anhydride, carboxylic acid, or ester


22 2.12.A2.A 3 3,5 44,5 5 5.5 0 7 I 910 11 12131a15t0lEm225


a 2.6 2.8 3 3.5 a 4.5




so

o


Wavenumb€r (cml )

Mims0)3.5 . .5 5 55 6 7 S 910


ao

c

E

IF2

Eo6

c

sF

oo

o

so

E6qt

21 2.4 2.E 3 11 12 13 1a 1510 11 82 25


Microns (p)5678910111213!415r8



4-


FogsE0po.Ee4

8a

EoEF

Microns 0422 2.4232.6 3 3.5 44.5 5 5.5 6 7 8 9r0 f i 12131a1514r8n25


Micmns (p)22 2.42.62.8 3 3-5 a4.5 5 5.56 7 E 910 11 12131ar5r61E626



1 2.6 2.8 g 3.3 a a.!Microns (F)

5.5 6 7 a 910 11 12 13 r . r l t I

@oo

EF


Wavonumbsr (cm-1)





0.0q601 >0.2803Ao.r P0.5 60.6 0

1.02.0

rf1ms&70@s{s10



22 2.12.A2.A 3 3,5 44,5 5 5.5 0 7 I 910 11 12131a15t0lEm225


a 2.6 2.8 3 3.5 a 4.5




so

o


Wavenumb€r (cml )

Mims0)3.5 . .5 5 55 6 7 S 910


ao

c

E

IF2

Eo6

c

sF

oo

o

so

E6qt

21 2.4 2.E 3 11 12 13 1a 1510 11 82 25


Microns (p)5678910111213!415r8



4-


FogsE0po.Ee4

8a

EoEF

Microns 0422 2.4232.6 3 3.5 44.5 5 5.5 6 7 8 9r0 f i 12131a1514r8n25


Micmns (p)22 2.42.62.8 3 3-5 a4.5 5 5.56 7 E 910 11 12131ar5r61E626



1 2.6 2.8 g 3.3 a a.!Microns (F)

5.5 6 7 a 910 11 12 13 r . r l t I

@oo

EF


Wavonumbsr (cm-1)





0.0q601 >0.2803Ao.r P0.5 60.6 0

1.02.0

rf1ms&70@s{s10



10

8) (8 pts) Provide a mechanistic explanation for the following reaction. Be sure to explain the regioselectivity of the reaction.

CH3CH2OHH+

OCH2CH3


11

9) (10 pts) Two diasteromeric sets of enantiomers, A/B and C/D, exist for 3-bromo-2-butanol.

When enantiomer A or B is treated with HBr, only racemic 2,3-dibromobutane is formed; NO meso isomer is formed. When enantiomer C or D is treated with HBr, only meso-2,3-dibromobutane is formed; NO racemic 2,3-dibromobutane is formed. Account for these observations using the reaction mechanism.

CH3

HHO

BrH

CH3

CH3

OHH

HBr

CH3

CH3

OHH

BrH

CH3

CH3

HHO

HBr

CH3

A B C D

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First Exam CHEM 256 – Organic Chemistry II Prof. Bastin ... · First Exam CHEM 256 – Organic Chemistry II Prof. Bastin Spring 2013 Name _____ Provide clear, concise answers using