Synthesis of β,β-Difluorohomoallylic Alcohols

Ando et al. have reported a new approach to synthesize β,β-difluorohomoallylic alcohols. According to their results, the treatment of ethyl 4,4-difluoro-3-(triethylsilyl)but-3-enoate with TBAF generates the gem-difluorocarbanion, which reacts with an aromatic aldehyde to afford ethyl (E)-4,4-difluoro-5-hydroxy-5-arylpent-2-enoate. This reaction is one of the few examples to activate the trialkylsilyl group of vinylsilanes and to use for the synthesis. Since β,β-difluorohomoallylic alcohol is a versatile intermediate for constructing an isostere of peptides, this approach is expected to be applied in the field of peptide chemistry.