A facile and stereoselective synthesis of 3,4,6-tri-O-acetyl-2-deoxy-2phthalimido-β-D-glucopyranosyl chloride.

Acetylation of D-glucosamine catalysed by sulfuric acid and N-phthaloylation of the glucosyl acetate yielded 1,3,4,6-tetra-O-acetyl-2-deoxy-2-phthalimido-α-D-glucopyranose. This gave the corresponding pure β-glucosyl chloride upon treatment with PCl₅-BF₃. An anomeric chlorination with thionyl chloride combined with the Lewis acids (ZnCl₂, SnCl₄ and BiCl₃) resulted in an α/β anomer mixture. [ABSTRACT FROM AUTHOR]