A stereoselective synthesis of silylated polyunsaturated halides from alpha,beta-epoxysilanes

A new synthetic approach to silylated polyunsaturated halides has been deve loped, starting from the readily available (1E,3E)-1,4-bis(trimethylsilyl)- 1,3-butadiene and (3E)-1,4-bis(trimethylsilyl)-3-buten-1-yne. A simple epox idation reaction, followed by regioselective cl-opening of the epoxide ring by metal halides affords the corresponding halohydrins with a high degree of stereoselectivity. A subsequent p-elimination reaction from these compou nds leads to (Z,E)-dienyl halides and to (Z)-enyne halides. (C) 2001 Elsevi er Science Ltd. All rights reserved.