Unit 5 Review Problems

Chem 2124 Unit 5 Review Problems

1. Draw the acetic acid dimer. Be sure to indicate the hydrogen bonds present.

2. Which of the following is the strongest acid? A) acetic acid B) chloroacetic acid C) bromoacetic acid D) fluoroacetic acid

3. Name the salt formed from the reaction of benzoic acid with ammonia.

4. What two alkenes, which contain only one double bond, yield exclusively propanoic acid upon oxidation with hot concentrated KMnO4?

5. 2-Phenylethanol yields what acid upon treatment with cold chromic acid? (look at the conditions)

6. 2-Phenylethanol yields what acid upon treatment with hot chromic acid or permanganate?

7. Suggest a sequence of synthetic steps through which phenylacetic acid can be prepared from toluene via a nitrile intermediate. 8. Provide a detailed, stepwise mechanism for the reaction of acetyl chloride with methanol to produce methyl acetate and HCl.

9. Which of the following conditions will drive the equilibrium of the Fischer esterification towards ester formation? A) addition of water B) removal of water as it is formed C) addition of an inorganic acid as a catalyst D) addition of alcohol E) both B and D

10. The first mechanistic step in the direct reaction of an amine with a carboxylic acid to produce an amide is: A) an acid-base reaction B) nucleophilic attack on the carbonyl carbon C) loss of H2O D) loss of CO2 E) loss of N2

11. Acid chlorides can be prepared from carboxylic acids by treatment with: A) (COCl)2 B) SOCl2 C) KCl D) both A and B E) both B and C

12. Provide the major organic product for the following reaction.

1) SOCl2

COOH 2) AlCl3

3) H2O

13. Provide a detailed, stepwise mechanism for the reaction of acetic anhydride with phenol.

14. Provide the structure of the following compounds.

cyclohexyl formate

γ-butyrolactam o-bromobenzoyl chloride

2-hydroxybenzoic acid succinic acid phosgene ethyl acetate

3-oxobutanenitrile

N-methyl-3-chloropropanamide

N,N-dimethylformamide

15. An unknown compound with a MW of 99 gave the following IR and NMR spectra. The broad NMR peak at 7.55 ppm disappears when the sample is shaken with D2O. Propose a structure that is consistent with this data.

1 15. Propose a synthetic route for each of the following.

16. Circle the best set of reagents or best series of steps that would produce the following conversion:

COOH CN

a. NaCN, acetone b. 1) LiAlH4 c. 1) B2H6 2) H2O 2) NH3 3) NaCN, acetone 3) Zn(Hg), HCl

d. 1) SOCl2 e. 1) SOCl2 2) NH3 2) NaCN 3) POCl3

O O C C O OCH3

+ a. 1) LiAlH4 b. 1) excess CH3OH, H , heat c) 1) NaOH(aq), heat 2) H2O 2) acetyl chloride 3) CH3Cl

+ d) 1) LiAlH4 e) 1) H , heat 2) H2O 2) NaOCH3 3) POCl3 4) CH3OH

CH2Br CH2CH2CO2H

CH3 CH2Br CH3 CH2CO2CH2CH3

O SOCl2 CO2H

CO2CH(CH3)2

The following NMR and IR spectra were obtained for a unknown sample. Based on this information propose a structure for the unknown material.

(Hint:The peak at 7.79 ppm is lost when D2O is added to the sample.)