A Novel Synthesis Including Asymmetric Synthesis of α,β-Unsaturated γ-Hydroxy Carbonyl Compounds from Enones with Carbon Homologation

Abstract

Abstract Reaction of the carbanion derived from 1-chloroalkyl aryl sulfoxides with enones gave 1,2-adducts in good yields. Treatment of the adduct with potassium benzenethiolate afforded α-phenylthio β,γ-unsaturated carbonyl compound through an α,β-epoxy sulfoxide. Oxidation of the sulfide with 2.1 equivalents of m-chloroperbenzoic acid gave α,β-unsaturated γ-phenylsulfinyloxy carbonyl compound via sulfoxide-sulfenate rearrangement. The sulfinate was easily hydrolyzed with aqueous potassium hydroxide to afford α,β-unsaturated γ-hydroxy carbonyl compound in good yield. When optically active (−)-1-chloroalkyl p-tolyl sulfoxides were used in this procedure, a synthesis of optically active α,β-unsaturated γ-hydroxy carbonyl compounds with moderate to good optical purity was realized.