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 address the problem, we must identify the chemical that transforms an aldehyde into a primary alcohol.

1. Reaction Principles:
- Aldehydes are converted to primary alcohols via reduction.
- Aldehydes are oxidized to carboxylic acids by oxidizing agents.
- Some reagents oxidize aldehydes without causing reduction.

2. Reagent Examination:
- PCC (Pyridinium chlorochromate): An oxidant that converts primary alcohols to aldehydes; it does not reduce aldehydes.
- $NaBH_4$ (Sodium borohydride): A mild reductant that reduces aldehydes to primary alcohols.
- $KMnO_4$ (Potassium permanganate): A potent oxidant that converts aldehydes to carboxylic acids.
- $HNO_3$ (Nitric acid): An oxidant, not a reductant.

3. Determination:
Only $NaBH_4$ can reduce aldehydes to primary alcohols.

Final Result:
The appropriate reagent is $ {NaBH_4} $ (Sodium borohydride).