Problem Set 5

Chem 220

Due : Monday, October 13, 1997

These problems cover chapters 7, 8, and 9

1. Consider the compound 2,3,4-tribromopentane. One might expect 2ⁿ=2³=8

stereoisomers. Owing to symmetry, there are only 4 stereoisomers. Which ones

are achiral? Which ones are enantiomers? What is true about changing the

configuration at C₃ in either one of the enantiomers? What is true about

changing the configuration at C₃ in either one of the achiral stereoisomers?

2. Dr. Knowitall proposes to convert (S)-2-bromobutane to (S)-2-deuteriobutane via a

Grignard reaction. Does s/he propose to do this with retention or inversion of

stereochemistry? Illustrate with structures. What surprise is in store for our

chemist?

3. Predict the products of the following reactions and write balanced equations.