Question

Which of the following reagents can convert an aldehyde to a primary alcohol?

• A. PCC (Pyridinium chlorochromate)
• B. $NaBH_{4} $(Sodium borohydride)
• C. $KMnO_{4}$ (Potassium permanganate)
• D. $HNO_{3}$ (Nitric acid)

Hint:

Use NaBH\textsubscript{4} for selective reduction of aldehydes and ketones to alcohols; it does not reduce carboxylic acids or esters.

Answer 1

The Correct Option is B

To solve the problem, we need to identify the reagent that can convert an aldehyde to a primary alcohol.

1. Understanding the Reaction:
- Aldehydes can be reduced to primary alcohols by reducing agents.
- Oxidizing agents typically convert aldehydes to carboxylic acids.
- Some reagents oxidize aldehydes without reducing them.

2. Analysis of Each Reagent:
- PCC (Pyridinium chlorochromate): An oxidizing agent that oxidizes primary alcohols to aldehydes but does not reduce aldehydes.
- $NaBH_4$ (Sodium borohydride): A mild reducing agent that reduces aldehydes to primary alcohols.
- $KMnO_4$ (Potassium permanganate): A strong oxidizing agent, converts aldehydes to carboxylic acids.
- $HNO_3$ (Nitric acid): An oxidizing agent, not a reducing agent.

3. Conclusion:
Only $NaBH_4$ is capable of reducing aldehydes to primary alcohols.

Final Answer:
The correct reagent is $ {NaBH_4} $ (Sodium borohydride).