Chem 3371 Fall 2014 Exam II Name: _________________________  

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Chem 3371 Fall 2014 Exam II Name: _________________________  

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Grade Sheet: Page 3: ____________ (6 pts) Page 4: ____________ (8 pts) Page 5: ____________ (6 pts) Page 6: ____________ (6 pts) Page 7: ____________ (4 pts) Page 8: ____________ (18 pts) Page 9: ____________ (18 pts) Page 10: ____________ (10 pts) Page 11: ____________ (14 pts) Page 12: ____________ (10 pts) Page 13: ____________ (10 pts) Total: ____________ (110 pts)

Chem 3371 Fall 2014 Exam II Name: _________________________  

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1. (2 pts) Classify the reaction below. (circle the best answer)

A. Substitution B. Elimination C. Addition D. none of the above 2. (2 pts) Classify the reaction below. (circle the best answer)

A. Substitution B. Elimination C. Addition D. none of the above 3. (2 pts) Classify the reaction below. (circle the best answer)

A. Substitution B. Elimination C. Addition D. none of the above 4.–6. Use the chart of equilibrium constants below to answer quetsions 4.–6.

+ N3

NN

N

OH

OTs

O

OH

OH O

R

H

H

R

(axial) (equatorial)

R

CH3

CH2CH3

CH(CH3)2

C(CH3)3

18

23

38

4000

Keq

Chem 3371 Fall 2014 Exam II Name: _________________________  

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4. (2 pts) Which R group shows the highest percentage of equatorial conformation at equilibrium? (circle the best answer):

5. (2 pts) Which R group shows the highest percentage of axial conformation at equilibrium? (circle the best answer):

6. (2 pts) Which R group has the most negative ΔGº? (circle the best answer):

7. (2 pts) For which of the following reactions will ΔSº have a significantly positive value (circle ALL that apply, there could be more than one answer):

CH3

CH2CH3

CH(CH3)2

C(CH3)3

A.

B.

C.

D.

E. none of the above

CH3

CH2CH3

CH(CH3)2

C(CH3)3

A.

B.

C.

D.

E. none of the above

CH3

CH2CH3

CH(CH3)2

C(CH3)3

A.

B.

C.

D.

E. none of the above

A.

B.

C.

D.

E. none of the above

+

CH3• + CH3• CH3CH3

CH3COOCH3 + H2O CH3COOH + CH3OH

OHOO OH

Chem 3371 Fall 2014 Exam II Name: _________________________  

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8. (2pts) Name the structure below (circle the best answer):

A. (7R)-7-iodo-4-isobutyl -2,3-dimethyloctane B. (7R)-4-sec-butyl-7-iodo-2,3-dimethyloctane C. (7S)-7-iodo-4-isobutyl -2,3-dimethyloctane D. (7S)-4-sec-butyl-7-iodo-2,3-dimethyloctane E. none of the above 9. (2 pts) Name the structure below (circle the best answer):

A. (2S,5R)-3-ethyl-2-methylheptan-6-ol B. (2S,5R)-5-ethyl-6-methylheptan-2-ol C. (2R,5S)-3-ethyl-2-methylheptan-6-ol D. (2R,5S)-5-ethyl-6-methylheptan-2-ol E. none of the above 10. (2 pts) Which alkyl halide will undergo the fastest SN2 reaction (circle the best answer)?

I

OH

I

Br

Cl

Br

A.

B.

C.

D.

Chem 3371 Fall 2014 Exam II Name: _________________________  

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11. (2 pts) Which alkyl halide will undergo the fastest SN1 reaction (circle the best answer)?

12. (2 pts) What is/are the major product(s) of the SN2 reaction below (circle ALL that apply, there could be more than one answer)?

13. (2 pts) What is/are the major product(s) of the SN1 reaction below (circle ALL that apply, there could be more than one answer)?

I

Br

Cl

Br

A.

B.

C.

D.

I+ NH2

A. B. C. D. E. none of the above

NHNH NHNH

IOH

OCH3

A. B. C. D.

E. none of the above

O

OCH3

O

OCH3

O

OCH3

O

OCH3

Chem 3371 Fall 2014 Exam II Name: _________________________  

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14. (2 pts) For the E2 reaction below, identify the MAJOR product (circle the best answer).

15. (2 pts) For the E2 reaction below, identify the MAJOR product (circle the best answer).

Chem 3371 Fall 2014 Exam II Name: _________________________  

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16. (4 pts) Which mechanisms would you predict for the following reaction (circle ALL that apply, there could be more then one answer):

A. SN1 B. SN2 C. E1 D. E2 E. none of the above 17. (4 pts) Which mechanisms would you predict for the following reaction (circle ALL that apply, there could be more then one answer):

A. SN1 B. SN2 C. E1 D. E2 E. none of the above 18. (4 pts) Which mechanisms would you predict for the following reaction (circle ALL that apply, there could be more then one answer):

A. SN1 B. SN2 C. E1 D. E2 E. none of the above 19. (3 pts) Which mechanisms would you predict for forming the indicated product in the following reaction (circle ALL that apply, there could be more then one answer):

A. SN1 B. SN2 C. E1 D. E2 E. none of the above 20. (3 pts) Which mechanisms would you predict for forming the indicated products in the following reaction (circle ALL that apply, there could be more then one answer):

A. SN1 B. SN2 C. E1 D. E2 E. none of the above

Br + KCN

I + KOC(CH3)3

Br CH3CH2OH

HO

pTSA:S

O

O

OH

H3C

OHH2SO4

Chem 3371 Fall 2014 Exam II Name: _________________________  

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Section 2: Drawing Structures 21. (4 pts) Draw two unique resonance structures for the molecule drawn below.

22. (4 pts) Draw two unique resonance structures for the molecule drawn below.

23. (5 pts) Assume the reaction below goes by an SN2 mechanism. Draw the mechanism and products. Be sure to indicate the stereochemistry.

24. (5 pts) Assume the reaction below goes by an E2 mechanism. Draw the mechanism and products. Be sure to indicate the stereochemistry.

NO

O

O

Cl + KCNDMSO

Cl + KOC(CH3)3DMSO

Chem 3371 Fall 2014 Exam II Name: _________________________  

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25. (5 pts) Draw the two major products from an SN1 reaction below in box A and B. Then draw a stepwise mechanism to form product A.

26. (5 pts) Draw the four major products formed from an E1 reaction below in boxes A B, C, and D. Then draw a stepwise mechanism to form product A.

Br HOCH2CH3

A B

Br HOCH2CH3

A B

C D

Chem 3371 Fall 2014 Exam II Name: _________________________  

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27. (5 pts) Draw a stepwise mechanism for the reaction below.

28. (3 pts) Draw the two major elimination products from the following reaction. Be sure to indicate stereochemistry.

29. (3 pts) Draw the major product(s) from the following reactions.

30. (3 pts) Draw the major products from the following reactions nucleophilic substitution reactions. Be sure to indicate stereochemistry.

H2SO4

OH

OH POCl3

pyrdine:N

Major Minor

OH SOCl2PBr3

O1. NaOCH3CH32. H2O

HOCH2CH3H2SO4

Chem 3371 Fall 2014 Exam II Name: _________________________  

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31. (10 pts) Your laboratory is stocked with the chemicals below. Using only these reagents and any solvents you need, show a stepwise synthesis of the alkyne below:

OHH H OH HBr NaH

SOCl2 PBr3

N SO

O

Cl

H3C

Your reagents and starting materials:

Your synthetic target:

H H +

OH+

Intermediate A

Intermediate A

+

OH +

+

+

Chem 3371 Fall 2014 Exam II Name: _________________________  

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32. (10 pts) Synthesize the compound below from 2-bromocyclohexanol. You may use any necessary reagents and any organic compounds with 2 carbons or less.

N3

HO

Br

HO+ any reagent and organic compoundswith 2 carbons or less

Chem 3371 Fall 2014 Exam II Name: _________________________  

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