Question

\(\text{C}=\text{O}_{\text{(Carbonyl group in aldehydes and ketones)}}+4[H]\xrightarrow[\Delta ]{\text{Zn-Hg, conc. HCl}}\underset{\text{(Methylene group)}}{-\text{CH}_{2}}+\text{H}_{2}\text{O}\)
Identify the name of above reaction.

• A. Mendius reduction
• B. Clemmensen Reduction
• C. Wolf-Kishner reduction
• D. Hofmann degradation

Hint:

Reduction of C=O to CH2 with zinc amalgam and concentrated HCl is a named reaction.

Answer 1

The Correct Option is B

Step 1: Reagent Based Identification
Acidic reducing medium with $\text{Zn-Hg/conc. HCl}$ means Clemmensen.

Step 2: Eliminate Others
Wolff-Kishner uses basic medium, Mendius reduction converts nitriles to amines, and Hofmann degradation converts amides to amines.

Step 3: Result
Option (B) is correct.

Final Answer:
Zinc amalgam with concentrated HCl is the signature of Clemmensen reduction. \[ \boxed{\text{(B) }\text{Clemmensen Reduction}} \]