AAMC FL Practice Exam

What is the primary reaction type involved in aldol condensation?

1. Aldol addition

2. Dehydration synthesis

3. Aldol dehydration

4. Condensation reaction

The correct answer is: Condensation reaction

Aldol condensation primarily involves a condensation reaction, which is characterized by the combination of two molecules with the loss of a small molecule, often water. In the context of aldol condensation, this process involves two aldehydes or ketones reacting in the presence of a base or acid to form an α,β-unsaturated carbonyl compound, accompanied by the elimination of water. In the first step of an aldol reaction, an enolate ion is formed from one of the carbonyl compounds, which then attacks the carbonyl carbon of another molecule, resulting in a β-hydroxy carbonyl compound. This intermediate then undergoes dehydration, where a molecule of water is eliminated, leading to the formation of the final product, which is an α,β-unsaturated carbonyl compound. While terms like aldol addition and aldol dehydration describe specific phases of the overall reaction process, the overarching classification of aldol condensation itself is best captured by referring to it as a condensation reaction, due to the loss of water that characterizes the transformation from reactants to products.