Stereoselective synthesis of 1,4-disubstituted 1,3-diene from aldehyde using organotitanium reagent

Abstract Organotitanium reagent generated from 1-t-butylthio-3-trimethylsilyl-1-propene condenses with aldehydes to give 1 -t-butylthio-(E,Z)-1,3-alkadienes in a single step via (E)-erythro-β-hydroxysilane in a highly regio- and stereoselective manner. 1,4-Dialkyl-1,3-diene is obtaind from the diene sulfide by cross coupling reaction with Grignard reagent in the presence of nickel catalyst. The utility of the method is illustrated by application to the synthesis of Spilanthol, a naturally occurring insecticide from Spilanthese olerancae in five steps.