Stetter reaction

The Stetter reaction is a chemical reaction, which is used in the synthesis of 1,4- diketones. Cyanide as starting materials of this reaction can be catalyzed by an aldehyde and a Michael acceptor, ( α, β -unsaturated ketone, see Michael addition ) are used. And α, β - unsaturated nitriles or esters may be reacted. The reaction is named after the German chemist Hermann Stetter.

Reaction mechanism

First, the cyanide ion adds reversibly to aldehydes. The alcoholate formed tautomerizes now to a carbanion, which then nucleophilic attack on the Michael acceptor. Cleaving of the catalytically added cyanide and subsequent keto -enol tautomerism the desired diketone is obtained.

Variants

In place of cyanide ions also produced from thiazolium ylides are used.

If α, β -unsaturated nitriles used as acceptors, as can be synthesized by the Stetter reaction γ - ketonitriles.