4-OXY-SUBSTITUTED 1-LITHIO-1,2-ALKADIENYL CARBAMATES: TRAPPING OF CONFIGURATIVELY STABLE ALLENIC CARBANIONS AND STEREOSPECIFIC 1,4-ELIMINATION FOR THE SYNTHESIS OF ALK-3-EN-1-YNYL CARBAMATES.

Article abstract of DOI:10.1016/S0040-4039(01)80989-8

4-Silyloxy-1,2-alkadienyl carbamates 10 on treatment with n-butyllithium form 1-lithio derivatives 12 of moderate configurative stability.After replacement of silyloxy for the better leaving group benzoyloxy in 11, anions 15 undergo stereospecific 1,4-eli