Reaction of silyl ketene acetals with epoxides: a new method for the synthesis of gamma-butanolides

Titanium tetrachloride promoted reaction of silyl ketene acetals with epoxides, followed by acidic work-up, affords butanolides in moderate/good yields. With epihalohydrins the reaction is regioselective and occurs at the less substituted end of the epoxide; the gamma-haloalkyl-gamma-butanolides thus obtained can be further transformed into various products. (C) 2004 Elsevier Ltd. All rights reserved