Chemistry - Carbonyl compounds Question with Solution | TestHub

Statement-1: Acyloin condensation reaction is used to prepare $\alpha$-hydroxy ketones.

This statement is TRUE. The product of the acyloin condensation is indeed an $\alpha$-hydroxy ketone. For example, two molecules of an ester, R-COOR', react to form R-CO-CH(OH)-R. The carbonyl carbon of one ester becomes the carbonyl carbon of the $\alpha$-hydroxy ketone, and the $\alpha$-carbon of the other ester becomes the carbon bearing the hydroxyl group.

General reaction scheme for Acyloin Condensation:

$$2R-COO{R}^{\prime }\stackrel{Na,inertsolvent}{\to }R-CO-CH(OH)-R+2R^{\prime }OH$$

Here, R-CO-CH(OH)-R is an $\alpha$-hydroxy ketone.

Statement-2: The reaction involves the intermolecular condensation of an ester in the presence of sodium metal.

This statement is also TRUE. The acyloin condensation is an intermolecular reaction (between two separate ester molecules) and it requires a strong reducing agent like sodium metal. The sodium metal acts as a one-electron donor, initiating a radical mechanism.

Mechanism overview:

1. Reduction of the ester by sodium metal to form a radical anion.

2. Dimerization of two radical anions.

3. Elimination of alkoxide (OR') to form a 1,2-diketone.

4. Further reduction of the 1,2-diketone by sodium metal to form an enediolate dianion.

5. Protonation of the enediolate dianion upon workup (e.g., with acid) to yield the $\alpha$-hydroxy ketone (acyloin).

Since both statements are true and Statement-2 correctly describes the nature of the reaction (intermolecular condensation of an ester in the presence of sodium metal) which leads to the product mentioned in Statement-1 ($\alpha$-hydroxy ketones), Statement-2 is a correct explanation for Statement-1.

The final answer is $\boxed{A}$