1,2-Metallate rearrangements involving reaction of 1-metallated glycals with organolithium reagents under copper(I) mediation give alkenylpolyol chains in 45-91% yield (19 examples). The reaction was applied to a formal synthesis of KRN7000 as well as a synthesis of a Δ5,6-ceramide derivative. 1,2-metallate rearrangement - retro-[1,4]-Brookrearrangement - 1-metallated glycals - cuprates - organolithiums