# Reduction of Carbonyl Groups to Methylene Groups

## Wolff-Kishner Reduction: Experimental Procedure

The Wolff-Kishner reduction is used in preparative chemistry for the of ketone carbonyl groups to the corresponding methylene groups. Additionally, the reaction is being used for the selective reduction of oxocarboxylic acids because carboxyl groups are not affected.

In the original version, ketone and hydazine hydrate are reacted to form the hydrazone which in turn is heated to 200$°C$ in an autoclave in the presence of sodium or sodium alkoxide.

Since the seminal report, the original procedure has been substituted by the simpler and less expensive Huang-Minlon modification. In this procedure, the ketone is reacted in the cold with an aqueous hydrazine hydrate solution in ethylene glycol followed by heating under reflux.

Page 6 of 8