EFFICIENT SYNTHESIS OF SUBSTITUTED 2-DIETHYLPHOSPHONYLBUTA-1,3-DIENES

Numerous new substituted 2-diethylphosphonylbuta-1,3-dienes 5 bearing various aryl or alkyl substituents at the 1- and 4-positions were conveniently prepared from 2-diethylphosphonyl homoallylic alcohols 3, by stereospecific dehydration with dicyclohexylcarbodiimide in the presence of a catalytic amount of copper(II) chloride. In some cases, alcohols 3, resulting from the nucleophilic addition of lithiated allylic phosphonates 2 to various aromatic or aliphatic aldehydes, were isolated in a pure diastereomeric form, leading to diastereomerically pure dienes 5 upon dehydration.