Stereoselective synthesis of alpha and beta-C-glucosides via radical cyclization with an allylsilyl tether. Control of the stereoselectivity by changing the conformation of the pyranose ring

An efficient method for preparing both 1 alpha- and 1 beta-C-glucosides hav ing a 3-hydroxypropyl group at the anomeric position via a radical cyclizat ion reaction with an allylsilyl tether was developed. The stereoselectivity of the radical cyclization can be controlled by the conformation of the py ranose ring, which is effectively manipulated by the hyroxyl protecting gro ups. (C) 2000 Elsevier Science Ltd. All rights reserved.