Direct Glycosylation of Unprotected and Unactivated Sugars Using Bismuth Nitrate Pentahydrate

GRAPHICAL ABSTRACT

Abstract

Bi(NO₃)₃, a low-cost, mild, and environmentally green catalyst, has been successfully utilized for Fischer glycosylation for the synthesis of alkyl/aryl glycopyranosides by reacting unprotected sugars, namely, D-glucose, L-rhamnose, D-galactose, D-arabinose, and N-acetyl-D-glucosamine with various alcohols in good to excellent yields. The glycosides were formed with high α-selectivity. Further, an expedient separation of α- and β-glycosides using silver nitrate–impregnated silica gel flash liquid chromatography has been developed.

Keywords:

• Fischer glycosylation
• Bismuth nitrate
• Carbohydrates
• Flash chromatography
• Separation