Which of the following statements about the Wolff-Kishner reduction (R2C=O with NH2NH2, KOH, ethylene glycol, heat) is/are correct?

The first stage is formation of a hydrazone.

The carbanion is protonated by the solvent to give R2CH2.

Deprotonation of the hydrazone N-H gives an anion that loses N2 to give a carbanion.

The first stage is formation of a hydrazone.

The carbanion is protonated by the solvent to give R2CH2.

Deprotonation of the hydrazone N-H gives an anion that loses N2 to give a carbanion.

The key N2-loss step requires strongly acidic medium.

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3o1107

Which of the following statements about the Wolff-Kishner reduction ( $R X_{2} C = O$ with $NH X_{2} NH X_{2}$ , KOH, ethylene glycol, heat) is/are correct?

AThe first stage is formation of a hydrazone.
BThe carbanion is protonated by the solvent to give $R X_{2} CH X_{2}$ .
CDeprotonation of the hydrazone N-H gives an anion that loses $N X_{2}$ to give a carbanion.
DThe key $N X_{2}$ -loss step requires strongly acidic medium.

Hydrazone formation precedes the base-promoted steps. The base removes N-H, the diazenyl anion loses

N X_{2}

to give a carbanion, and the carbanion is protonated by the solvent. The reaction is carried out in strongly basic, not acidic, medium.