SYNTHESIS OF DIALKYL 2-(1-CYANO-2-OXO-1-PHENYL-ALKYL)-3-(TRIPHENYL-λ⁵-PHOSPHANYLIDENE)-SUCCINATES

Abstract

3-Oxo-2-phenyl-butanenitrile or 3-oxo-2-phenyl-pentanenitrile undergo a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine to produce highly-functionalized salt-free ylides in nearly quantitative yields. These stabilized phosphorus ylides exist as a mixture of two geometrical isomers as a result of restricted rotation around the carbon-carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group.

Keywords:

• Acetylenic esters
• CH-acid
• rotational isomers
• stable phosphorus ylides
• triphenylphosphine