Question

Aldol condensation between which of the following compounds followed by dehydration gives 4-Methylpent-3-en-2-one.

• A. Two Molecules of CH3COCH3
• B. Two Molecules of CH3CHO
• C. CH3CHO and HCO
• D. CH3CHO and CH COCH

Answer 1

Answer: (A)

Two Molecules of CH3COCH3

Answer 2

The structure of 4-Methylpent-3-en-2-one suggests that it is derived from a pentanone (5-carbon ketone) with a methyl group attached to the fourth carbon and a double bond between the third and fourth carbon.
Among the given options, the correct choice is (A) Two molecules of CH3COCH3 (acetone).
In this case, acetone (CH3COCH3) acts as both the enol and the carbonyl compound. The aldol condensation between two molecules of acetone can form a β-hydroxy ketone intermediate. Subsequent dehydration of the β-hydroxy ketone will lead to the formation of 4-Methylpent-3-en-2-one.
Therefore, the correct choice is (A) Two molecules of CH3COCH3 (acetone).