Synthesis of β,β-Difluoro-γ,δ-unsaturated Carboxylic Esters Using Claisen Rearrangement

Abstract

Treatment of α-(1-chloro-2,2-difluoroethenyl) alcohols with triethyl orthoacetate in the presence of propanoic acid gave ethyl γ-chloro-β,β-difluoro-γ,δ-unsaturated carboxylates in good yields. This method provides a convenient synthesis of the title compounds from CF3CHBrCl (1) and carbonyl compounds.