Chemistry 331 - Fall 1996

Chapter 6 - Stereochemistry

Practice Exercises

Chiral Centers - R & S Designations

Give complete names for the following compounds, including designation of R or S, where appropriate.


Reaction Stereochemistry

One step in the citric acid cycle (or Krebs cycle) is shown below:

Biochemists usually use the names "fumarate" and "malate" -- why?

How would you apply the Markovnikov Rule to this reaction?

An organic chemist would carry out this reaction using H2SO4 as catalyst -- write the reaction mechanism and predict the stereochemistry of the chiral product.

Mother Nature carries out this reaction using an enzyme (fumarase). Although you won't know the mechanism, make a prediction about the stereochemistry.

 

Maleic acid is the cis stereoisomer of fumaric acid.

What would be different in the case of the H2SO4-catalyzed reaction?

What would be different in the enzyme-catalyzed reaction?