Stereoselective lithiation of α,β-epoxy-γ,δ-vinylsilanes and transformation into α-silylated ketones

A (cis)α,β-epoxy-γ,δ-vinyl-silane undergoes lithiation α to the silicon atom with retention of the configuration of the oxirane. This leads to new silylated vinyloxiranes with a quaternary silylated stereogenic carbon atom. We show here the possible and efficient rearrangement of a methyl substituted adduct into a β,γ-unsaturated-α-silylated ketone.