JEE Chemistry 2025 Question with Solution

Given: The substrate is $\text{Ph-CO-CHO}$ and it is treated with $\text{KOH}$ under heat.

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

This is identified as a Cannizzaro reaction of an aldehyde lacking $\alpha$-hydrogen. In $\text{Ph-CO-CHO}$, the aldehyde group is more reactive toward base than the ketone group.

The key transformation is disproportionation of the aldehyde functionality in strong base. The aldehyde part is converted into a carboxylate, while reduction gives the adjacent carbon as an alcohol-bearing center.

Therefore, the major product is $\text{Ph-CH(OH)-COO}^-\text{K}^+$.

So, the correct option is B.

Given: The compound is an $\alpha$-keto aldehyde, $\text{Ph-CO-CHO}$, and the reagent is $\text{KOH}$ with heat.

Find: The major product after reaction.

The extracted solution states that this reaction proceeds through a Cannizzaro-type pathway because the aldehyde lacks $\alpha$-hydrogen.

1. Hydroxide attack: $\text{OH}^-$ attacks the aldehyde carbonyl carbon.
2. Hydride transfer: The intermediate transfers hydride during the Cannizzaro process.
3. Product formation: The oxidized product becomes a carboxylate salt in basic medium, and the reduced center becomes alcohol-bearing.

The solution explicitly concludes: Therefore, the major product (P) is $\text{Ph-CH(OH)-COO}^-\text{K}^+$.

There is unrelated material in one extracted approach discussing ether cleavage with $\text{HBr}$, but the relevant chemistry for this question is the second approach, which matches the given substrate and reagents. Hence the answer is determined from the matching solution.

Therefore, the correct option is B.