Question

The structural feature in carbonyl compound for Aldol condensation is:

• A. Presence of at least one β-hydrogen
• B. Presence of at least one α-hydrogen
• C. Concentrated base
• D. Lack of α-hydrogen

Hint:

Aldol condensation requires the presence of α-hydrogen to form the enolate ion for the reaction to proceed.

Answer 1

The Correct Option is B

Step 1: Understanding Aldol Condensation.
Aldol condensation is a reaction where a β-hydroxy ketone or aldehyde is formed by the reaction of two molecules of aldehydes or ketones in the presence of a base. The reaction involves the formation of an enolate ion from the α-hydrogen.
Step 2: The Role of α-Hydrogen.
The key feature for Aldol condensation is the presence of an α-hydrogen, as this hydrogen is removed by the base to form the enolate ion, which then attacks the carbonyl carbon of another molecule.
Step 3: Other Options.
- Option 1: β-hydrogen is not the correct answer, as the α-hydrogen is critical for the reaction.
- Option 3: Concentrated base is required for the reaction, but the presence of α-hydrogen is the defining feature.
- Option 4: Lack of α-hydrogen would prevent the formation of the enolate, stopping the reaction.
Final Answer: \[ \boxed{\text{The correct answer is the presence of at least one α-hydrogen.}} \]