Synthesis of <i>S</i>-Glycosyl Primary Sulfonamides

The synthesis of <i>S</i>-glycosyl sulfonamides wherein the primary sulfonamide functional group (−SO<sub>2</sub>NH<sub>2</sub>) is directly attached to the anomeric position of a carbohydrate moiety is reported. Our general approach consists of first introducing a thioacetate group at the anomeric center of a per-<i>O</i>-acetylated sugar derivative. From this follows formation of a glycosyl sulfenamide (sugar-SNR<sub>2</sub>), oxidation of the sulfenamide to give a glycosyl N-protected sulfonamide (sugar-SO<sub>2</sub>NR<sub>2</sub>), and removal of the sulfonamide protecting (R) group to yield a primary sulfonamide at the anomeric center (sugar-SO<sub>2</sub>NH<sub>2</sub>). A variety of mono- and disaccharide derivatives were synthesized using this new methodology.