Synthesis of γ-methylene oxacycles and α- and β-alkylidene lactones via silicon-assisted ring opening of cyclopropyl carbinols

Abstract

Cyclopropyl carbinols bearing a (tert-butyldiphenylsilyl)methyl substituent undergo silicon-assisted regioselective ring cleavage and the resulting β-silyl carbocation is intramolecularly trapped with hydroxy and ester functions to generate γ-methylene oxacycles and α- and β-alkylidene lactones without the cleavage of the silicon function. © 2002 The Royal Society of Chemistry.