Questions: Consider the stereoisomers (A-E) drawn below: Which structure is an enantiomer of structure A? structure B structure C structure D structure E

Solution Steps

• Structure A has the following groups around the chiral center: CHO, Br, NH2, and CH2OH.
• Determine the configuration (R or S) of structure A by assigning priorities to the groups based on atomic number and using the Cahn-Ingold-Prelog priority rules.

• Similarly, determine the configuration (R or S) of structures B, C, D, and E by assigning priorities to the groups around their chiral centers.

• An enantiomer is a non-superimposable mirror image of the original molecule, meaning it will have the opposite configuration (R vs. S) at the chiral center.
• Compare the configurations of structures B, C, D, and E with that of structure A to find the one with the opposite configuration.

Final Answer