Synthesis of alkenes by the reaction of magnesium sulfone derivatives witharylsulfonylhydrazones of aldehydes

A new procedure for synthesis of alkenes starting from aldehydes and sulfon es is described. Aldehyde hydrazones 1 or 4 on treatment with magnesium der ivatives of representative phenyl alkyl sulfones or dialkyl sulfones afford the respective alkenylation products (2a-e and 5) in excellent yields. Rea ction of 1 or 4 with selected lithiathed sulfones was found sensitive to th e steric hindrance and tending to yield the respective Shapiro reaction pro ducts 3 and 6, predominantly.