Organic Chemistry III

Professor Carl C. Wamser

Exam 1 Answer Key

 Chem 336 - Spring 2005

1. (15 points) Write complete names for each of the following, including stereochemistry if it is specifically shown.

a)

potassium 2,2-dimethyl-3-oxopentanoate

b)

(S)-2-methyl-2,3-diphenylpropanenitrile

c)

methyl 4-(dimethoxymethyl)benzoate

d)

trans-4-tert-butylcyclohexyl formate OR

trans-4-(1,1-dimethylethyl)cyclohexyl methanoate

e)

2-(p-cyanophenyl)-N-ethylethanamide

2. (15 points) Write accurate structures for each of the following:

a) the hydrate of p-nitrobenzaldehyde

b) the enolate anion of tert-butyl ethyl ketone

c) any delta-lactam

d) pentanedioic anhydride

e) cis-4-isobutylcyclohexanecarboxylic acid

3. (15 points) Write all the resonance forms for the intermediate that would be formed in the first step of each of the following reactions. (Just the step described - don’t try to finish the reaction.)

Add H+ to the most basic site:

a)

b)

Remove H+ from the most acidic site:

c)

Add OH- to the beta-position:

d)

4. (15 points) Complete each of the following reactions by adding the missing part: either the necessary reagents and conditions or the expected major product.

a)

b)

c)

d)

e)

5. (15 points) Write a complete mechanism for the formation of the dimethyl acetal of cyclobutanone. Show all steps and show all resonance forms for any intermediates.

6. (10 points) Write a complete mechanism for the base-catalyzed aldol condensation (with dehydration) of phenylacetaldehyde. Show all steps and show all resonance forms for any intermediates.

7. (15 points) The following retrosynthetic analysis was developed for the preparation of the target compound phenylalanine. Show the sequence of reactions from benzaldehyde that would be used to make phenylalanine.