The Conversion of Carbonyl Compounds into Pentadienylamines by a Julia-Kocienski Olefination Procedure

Abstract

Julia-Kocienski olefination has been successfully employed to convert carbonyl compounds into the corresponding Boc-protected 1,3-pentadienyl amines in a C4N homologation process. Good to excellent yields are achieved in THF using MHMDS as base to deprotonate the precursor 1-phenyl-1H-tetrazol-5-ylsulfone reagent. The nature of the metallic countercation dramatically affects the stereoselectivity of the newly formed alkene: good levels of 2E,4E-stereoselectivity are achieved using KHMDS whereas LiHMDS gives a predominance of the 2E,4Z-dienyl product.