Question

The reagent, from the following, which converts benzoic acid to benzaldehyde in one step is

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is A

To convert benzoic acid to benzaldehyde in one step, we need a specific reducing agent that selectively reduces the carboxylic acid group to an aldehyde group without further reduction to an alcohol. The reagent needed for this transformation is di-isobutylaluminum hydride (DIBAL-H).

DIBAL-H selectively reduces esters, nitriles, and carboxylic acids to aldehydes at low temperatures.

1. Mechanism: When DIBAL-H is used in controlled conditions, it adds to the carbonyl group of the carboxylic acid, forming an intermediate that can be hydrolyzed to yield the aldehyde.
2. Conclusion: Therefore, DIBAL-H is the appropriate reagent for converting benzoic acid to benzaldehyde in a single step.

Other options do not provide this selective reduction without further reducing benzaldehyde to benzyl alcohol.