Wolff-Kishner reduction

In 1912 he published a new reaction now known as the Wolff-Kishner reduction.

A hydrazone is an intermediate in the Wolff-Kishner reduction.

Hydrazine and potassium hydroxide give limonene (6) via a Wolff-Kishner reduction.

The Wolff-Kishner reduction is a chemical reaction that fully reduces a ketone (or aldehyde) to an alkane.

For example, a ketone can be reduced down completely if made into a hydrazine and then treated with sodium ethoxide (Wolff-Kishner reduction).

Hydrazine (Wolff-Kishner reduction)

This reaction, introduced in 1961 by P.S. Wharton, is an extension of the Wolff-Kishner reduction.

If desired, the resulting ketone can be subsequently reduced to the corresponding alkane substituent by either Wolff-Kishner reduction or Clemmensen reduction.

Acid sensitive substrates should be reacted in the Wolff-Kishner reduction, which utilizes strongly basic conditions; a further, milder method is the Mozingo reduction.

The 4-acetyl group could easily be reduced to a 4-ethyl group by use of the Wolff-Kishner reduction (hydrazine and alkali, heated); hydrogenolysis, or the use of diborane.

It's a short-cut for the Wolff-Kishner reduction and involves heating the carbonyl compound, potassium hydroxide, and hydrazine hydrate together in ethylene glycol in a one-pot reaction.

This method is much milder than either the Clemmensen or Wolff-Kishner reductions, which employ strongly acidic or basic conditions respectively that might interfere with other functional groups present in the molecule.

Hydrazine is used in the Wolff-Kishner reduction, a reaction that transforms the carbonyl group of a ketone into a methylene bridge (or an aldehyde into a methyl group) via a hydrazone intermediate.