GRAPHICAL ABSTRACT
Abstract
This article describes the stereoselective synthesis of quercetin 3-O-glycosides of 2-amino-2-deoxy-d-glucose. Efficient 1,2-trans-glycosylation of protected quercetin with N-acetyl-protected 2-amino-2-deoxy-d-glucose chloride was achieved under phase transfer catalytic conditions in a 0.15 M aqueous K2CO3/chloroform system using tetrabutylammonium bromide as the catalyst. On the contrary, glycosylation with the N-phthalimido-protected bromide donor under the same conditions was found to give predominantly 1,2-cis-glycoside product.