Synthesis of α-Alkylated (Z)-γ-Fluoro-β,γ-enoates through Organocopper Mediated Reaction of γ,γ-Difluoro-α,β-enoates: A Different Reactivity of R3Al-Cu(I) and Me2CuLi

Reaction of γ,γ-difluoro-α,β-enoates having a δ-hydroxyl group with trialkylaluminum (R3Al) in the presence of CuI•2LiCl proceeded in SN2′-type manner to give α-alkylated (Z)-γ-fluoro-β,γ-enoates, while reductive defluorination of γ,γ-difluoro-α,β-enoates with Me2CuLi followed by reaction with alkyl halides provided the corresponding (Z)-α-alkylated products.