Nucleophilic Addition of Hydrazine The Wolff-Kishner Reaction

Nucleophilic Addition of Hydrazine The Wolff-Kishner Reaction 

Ludwig Wolff (1857-19191 was bom in Neustadt/Hardt, Germany, and received his Ph.D. from the University of Strasbourg working with Rudolf Fittig. He was professor of chemistry at the University of Jena. 

A useful variant of the imine-forming reaction just discussed involves the treatment of an aldehyde or ketone with hydrazine, H2NNH2, in the presence of KOH. Called the Wolff-Kishner reaction, the process is a useful and general method for converting an aldehyde or ketone into an alkane, R C O- R2CH2. 

Kishner (1867-19351 was born in Moscow and received his Ph.D. atthe University of Moscow working with Vladimir Markovnikov. He became professor, first atthe University of Tomsk and then atthe University of Moscow. 

The Wolff-Kishner reaction involves formation of a hvdrazone intermedi- 

Note that the Wolff-Kishner reduction accomplishes the same overall transformation as the catalytic hydrogenation of an acylbenzene to yield an alkyl-benzene (Section 16.10). The Wolff-Kishner reduction is more general and more useful than catalytic hydrogenation, however, because it works well with both alkyl and arvl ketones. 

CHAPTER 19 I Aldehydes and Ketones Nucleophilic Addition Reactions 

Show how you could prepare the following compounds from 4-methyl-3-penten-2-one, (CH3)2C=CHC0CH3- 

Mechanism of the WolfF-Kishner reduction of an aidehyde or ketone to yieid an aikane. 

I Reaction of the aldehyde or ketone with hydrazine yields a hydrazone in the normal way. 

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