1,2-Anhydrosaccharides and 1,2-Cyclic Sulfites as Saccharide Donors in Convergent Synthesis of Glucopyranosyl-, Mannopyranosyl- and Ribofuranosylbenzocamalexin

A convergent synthesis of 1-(β-D-glucopyranosyl)-, 1-(α-D-mannopyranosyl)- and 1-(β-D-ribofuranosyl)benzocamalexin was elaborated as an alternative route to the linear approach based on the indoline-indole method. 1,2-Anhydrosaccharides and 1,2-cyclic sulfites as saccharide donors were used in the key glycosylation step. Coupling with benzocamalexin resulted in moderate to excellent yields of nucleoside analogs, depending on the saccharide donor, catalyst and solvent used.