MCAT Organic Chemistry Question 103: Answer and Explanation

Home > MCAT Test > MCAT organic chemistry practice tests

Test Information

Question: 103

13. When benzaldehyde is reacted with acetone, which will act as the nucleophile?

  • A. Benzaldehyde, after addition of strong acid
  • B. Benzaldehyde, after reaction with strong base
  • C. Acetone, after addition of strong acid
  • D. Acetone, after reaction with strong base

Correct Answer: D

Explanation:

Because benzaldehyde lacks an α-proton, it cannot be reacted with base to form the nucleophilic enolate carbanion. Therefore, acetone will act as our nucleophile, and both choices (A) and (B) can be eliminated. In order to perform this reaction, which is an aldol condensation, acetone will be reacted with a strong base—not a strong acid—in order to extract the α-hydrogen and form the enolate anion, which will act as a nucleophile.

Previous       Next