Answer: NH2NH 2 and KOH in ethylene glycol.
- A Zn(Hg) amalgam and concentrated HCl (Clemmensen conditions)
- B NH2NH<sub>2</sub> and KOH in ethylene glycol
- C LiAlH<sub>4</sub> dissolved in anhydrous ether
- D NaBH<sub>4</sub> dissolved in ethanol
Correct answer: B. NH2NH<sub>2</sub> and KOH in ethylene glycol
Explanation: Wolf-Kishner reduction uses hydrazine and base (KOH) at high temperature to reduce C=O to -CH<sub>2</sub>-.
Curved arrows show the nucleophile attacking the carbonyl carbon while the C=O pi electrons move onto oxygen, giving a tetrahedral alkoxide intermediate.
Concept context
Aldehydes, ketones, carboxylic acids, and their derivatives (esters, amides, acid chlorides). Key reactions include nucleophilic addition, Aldol condensation, Cannizzaro, and Claisen. Very heavily tested in JEE and NEET.
Read the full Aldehydes, Ketones and Carboxylic Acids notes →