Addition of allylstannanes to glycal epoxides. A diastereoselective approach to β-C-glycosidation

Article abstract of DOI:10.1016/S0040-4039(98)00138-5

A new method for the synthesis of β-C-allyl glycosides has been developed for use in the synthesis of the spongipyran macrolides. Functionalized dihydropyrans are transformed to cis tetrahydropyrans via a two step process: i) epoxidation using dimethyldioxirane and ii) Lewis acid mediated epoxide opening with allylstannanes as nucleophiles. This protocol which can be successfully applied to complex systems, augments the limited body of methodology available for the preparation of β-configured C- glycosides.