Synthesis of sulfonamide-conjugated glycosyl-amino acid building blocks

The efficient synthesis of novel glycoconjugate amino acid building blocks wherein the amino acid and carbohydrate moieties are linked via a sulfonamide functional group is reported. The general reaction sequence consists of coupling a glycosyl thioacetate to an amino acid methyl ester followed by oxidation and deprotection of the carbohydrate moiety. We demonstrate the synthesis of derivatives from a range of amino acids, with reaction at either the α-amino group of amino acid precursors or the sidechain ε-amino group of lysine precursors.