Method for the preparation of O-protected glycosyl fluorides

摘要

Glycosyl halides which are O-acylated or O-alkylated at least in the 2-position are transhalogenated with alkali metal hydrogen difluorides in a polar-aprotic solvent and, if appropriate, the product is anomerized with the addition of less than the stoichiometric amounts of an inorganic fluoride with a Lewis acid character. Depending on the substrate, the glycosyl fluorides with the 1,2-trans or 1,2-cis configuration are obtained.