Remarkable difference in reactivity of ordinary vinylcopper reagents and vinylzinc halide containing a copper salt towards γ-mesyloxy-α,β-enoates. Synthesis of homochiral 1,4-dienes

Article abstract of DOI:10.1016/S0040-4020(01)80217-9

Whereas the reaction of γ-mesyloxy α,β-enoates with vinyl-Cu(CN)M or (vinyl)₂Cu(CN)M₂ (M = Li or MgX) yielded a reduction product with an (E)-double bond at the β,γ-position, treatment of the same substrates with 'higher order' zinc