Question

Which of the reactions is used in the conversion of a ketone into hydrocarbon ?

• A. Reimer-Tiemann reaction
• B. Wolff-Kishner reduction
• C. Aldol condensation
• D. Stephen reaction

Hint:

Remember the two famous reactions used to convert aldehydes and ketones into hydrocarbons: 1. Wolff-Kishner Reduction : \(NH_2NH_2/KOH,\ Heat\) (Basic medium) 2. Clemmensen Reduction : \(Zn(Hg)/HCl\) (Acidic medium) Both reactions remove the oxygen atom of the carbonyl group completely and convert the compound into the corresponding hydrocarbon.

Answer 1

The Correct Option is B

Step 1: Identify the transformation needed.
Converting a ketone $R\text{-}CO\text{-}R'$ to a hydrocarbon $R\text{-}CH_2\text{-}R'$ means completely removing the carbonyl oxygen and replacing it with hydrogen. Both the C and O bond must be broken.
Step 2: Recall the two classic full-reduction methods.
Clemmensen reduction uses $Zn\text{-}Hg$ in concentrated $HCl$ (acidic medium). Wolff-Kishner reduction uses hydrazine $NH_2NH_2$ followed by strong base $KOH$ and heat (alkaline medium). Both achieve $\gt C=O \rightarrow \gt CH_2$.
Step 3: Rule out the other options.
Reimer-Tiemann reaction introduces $-CHO$ into phenols. Aldol condensation joins two carbonyl compounds into a larger molecule. Stephen reaction converts $R-CN$ to $R-CHO$. None of these remove the carbonyl oxygen. Only Wolff-Kishner fits.
\[ \boxed{\text{Wolff-Kishner reduction}} \]