Question

Identify the reaction so that carbonyl group of aldehydes and ketones is reduced to methylene group on treatment with Zinc-amalgam and concentrated hydrochloric acid.

• A. Wolf-Kishner reduction.
• B. Stephan reaction.
• C. Clemmensen reduction.
• D. Etard reaction.

Hint:

Clemmensen = Acidic conditions ($HCl$); Wolff-Kishner = Basic conditions ($KOH$).

Answer 1

The Correct Option is C

Step 1: Concept
Reduction of the $>C=O$ group to $-CH_2-$ group.

Step 2: Analysis
- Clemmensen reduction: Uses $Zn-Hg$ and conc. $HCl$. - Wolff-Kishner reduction: Uses Hydrazine ($NH_2NH_2$) and $KOH$.

Step 3: Conclusion
Treatment with Zinc-amalgam and $HCl$ is specifically the Clemmensen reduction.
Final Answer: (C)