Question

Which of the following reagent is suitable for the preparation of the product in the above reaction ? (reaction of ketone to alkane)

• A. NaBH4
• B. NH2-NH2/C2H5ONa
• C. Ni/H2
• D. Red P + Cl2

Hint:

Wolff-Kishner is best for base-stable molecules; Clemmensen is best for acid-stable molecules. Both achieve the same result: $>C=O \to >CH_2$.

Answer 1

The Correct Option is B

Step 1: To convert a Carbonyl group ($>C=O$) directly into a Methylene group ($>CH_2$), we use deoxygenation methods.
Step 2: Wolff-Kishner Reduction uses Hydrazine ($NH_2NH_2$) and a strong base (like $KOH$ or $C_2H_5ONa$) in ethylene glycol.
Step 3: Clemmensen Reduction ($Zn(Hg)/HCl$) is the other common method.
Step 4: $NaBH_4$ and $H_2/Ni$ would only reduce the ketone to an alcohol.