Question

Statement-I: Reduction of ester by DIBAL-H followed by hydrolysis gives aldehyde.
Statement-II: Oxidation of benzyl alcohol with aqueous KMnO₄ leads to the formation of benzaldehyde.
Among the above statements, identify the correct statement.

• A. Statement-I is true but statement-II is false
• B. Statement-I is false but statement-II is true
• C. Both statements-I and II are true
• D. Both statements-I and II are false

Hint:

DIBAL-H is selective in reducing esters to aldehydes. Strong oxidizing agents like KMnO₄ oxidize benzyl alcohol to benzoic acid.

Answer 1

The Correct Option is A

Statement-I is true. DIBAL-H (Diisobutylaluminum hydride) is a reducing agent commonly used to reduce esters to aldehydes under mild conditions. After reduction by DIBAL-H, hydrolysis of the resulting intermediate leads to the formation of aldehyde. \[ \text{Ester} \xrightarrow{\text{DIBAL-H}} \text{Aldehyde} \xrightarrow{\text{Hydrolysis}} \text{Aldehyde} \] Statement-II is false. Oxidation of benzyl alcohol with KMnO₄ (potassium permanganate) typically results in the formation of benzoic acid, not benzaldehyde. KMnO₄ is a strong oxidizing agent that oxidizes alcohols to carboxylic acids, so it cannot be used to selectively form benzaldehyde from benzyl alcohol. Thus, the correct answer is that Statement-I is true and Statement-II is false.