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: - {Clemmensen reduction} → Acidic conditions (Zn-Hg/HCl) - {Wolff-Kishner reduction} → Basic conditions (Hydrazine + KOH) Both convert carbonyl groups into hydrocarbons.

Answer 1

The Correct Option is B

To solve the question regarding the conversion of a ketone into a hydrocarbon, we need to consider the reactions listed and select the one that accomplishes this transformation.

1. Reimer-Tiemann reaction: This is primarily used for the ortho-formylation of phenols, not for the reduction of ketones to hydrocarbons. Therefore, it is not suitable for the desired conversion.
2. Wolff-Kishner reduction: This reaction is specifically used to reduce carbonyl compounds such as aldehydes and ketones to hydrocarbons. In this process, a ketone is converted to a hydrocarbon by removal of the carbonyl oxygen as water and subsequent hydrogenation of the resulting intermediate. The general reaction is:

\(RCOR' + NH_2NH_2 \rightarrow RCH_2R' + N_2 + H_2O\)

1. Since this reaction directly converts ketones into hydrocarbons, it is the correct answer.
2. Aldol condensation: This is a reaction that involves the formation of a β-hydroxy ketone (or aldehyde) from two aldehydes or ketones. It does not reduce a ketone to a hydrocarbon.
3. Stephen reaction: This is used to convert nitriles to aldehydes, not for reducing ketones to hydrocarbons.

Based on the analysis above, the Wolff-Kishner reduction is used for the conversion of a ketone into a hydrocarbon, making it the correct answer.