Vinyl silane precursors for intramolecular ene reaction were prepared either by sequential organometallic substitution of appropriate silyl halides or by ring opening of oxasilacyclopentanes with 2-propenyllithium. The oxasilacyclopentane intermediates were prepared by free-radical cyclisation, intramolecular hydrosilylation, or intramolecular Diels-Alder reaction. Treatment of the ene precursors with methylaluminium dichloride resulted in the formation of silacyclohexanols with high stereoselectivity. (C) 2000 Elsevier Science Ltd.
