JEE Chemistry 2025 Question with Solution

Given: The substrate is treated with $\text{Zn-Hg}$ and $\text{HCl}$.

Find: The correct product (P) formed in this reaction.

Clemmensen reduction converts aldehydes and ketones into the corresponding hydrocarbon groups under strongly acidic conditions, while the ester group remains unchanged.

From the given structure:

• the ketone side chain is reduced to $-\text{CH}_2-$ in the side chain,
• the aldehyde group is reduced to $-\text{CH}_3$,
• the ester group is not reduced.

So we must select the option in which the ketone becomes an alkyl side chain, the aldehyde becomes a methyl group, and the ester remains as an ester.

The solution states that Option (2) correctly matches this transformation.

Therefore, the correct option is B.

Given: A compound containing ketone, aldehyde, and ester groups is subjected to Clemmensen reduction.

Find: Which option represents the product.

Identify principle: Clemmensen reduction selectively reduces carbonyl groups of aldehydes and ketones in acidic medium.

Apply reaction rule:

The ester group remains unchanged under these conditions.

Evaluate options:

1. Options showing alcohol formation are incorrect because Clemmensen reduction does not convert these groups into alcohols.
2. The correct structure must retain the ester and remove the aldehyde and ketone oxygen atoms.
3. The option identified in the provided solution is Option (2).

Therefore, the correct option is B.