Chem 240 - Spring 1999

Third Exam, March 31, 1999

1. (8) Give correct IUPAC names for the following compounds.

a.
b.

 

 

2. (8) Draw structures which correspond to the following IUPAC names.

a. 2-ethyl-1-butanamine b. heptylamine

 

 

 

 

 

 

3. (16) a. Circle the strongest base. Underline the weakest base.

b. Circle the structure of the compound which reacts fastest in an SN2 reaction. Underline the structure of the compound which reacts slowest in an SN2 reaction.

c. Circle the structure of the compound which reacts fastest in an SN1 reaction. Underline the structure of the compound which reacts slowest in an SN1 reaction.

d. Circle the formula which best represents the structure of phenylalanine at pH = 2.0. Underline the formula which best represents the structure of phenylalanine at pH = 5.5.

4 (24) Write appropriate formulas for the products of the following reactions. Be clear about stereochemistry where required.

a.

 

b.

 

c.

 

d.

 

e.

f.

 

5. (18) For each of the following reactions, place the structure of the needed reactant in the box.

 

a.

cf. 16.30c

 

b.

 

 

c.

 

 

 

6. (10) Show how you could carry out the following synthetic scheme by listing the necessary reagents in the proper sequence.

7. (8) Write out the steps in the mechanism of the following reaction. Briefly explain why you chose this mechanism.

 

 

 

 

 

 

 

8. (8) Briefly outline the reasons for the specificity of the base pairing scheme shown below. (In other words, why do we not see base pairs like A-G and G-T?)