Metallate complexes bearing a 1-hetero-1 -alkenyl ligand undergo rearrangment via a 1,2-alkyl shift. The reaction generally proceeds with inversion of configuration on displacement of the heteroatom substituent. Metallate complexes of Al, B, Cu, Ni, Zn, and Zr participate in the reaction. The organocuprate reaction provides the first connective and stereoselective synthesis of alkenyl-lithiums and alkenylcuprates from alkylcuprates and metallated enol ether derivatives. © 1990, IUPAC.