Synthesis of S-linked glycosyl amino acids in aqueous solution with unprotected carbohydrates

[GRAPHICS] The cyclic sulfamidate 5 was synthesized in 60% overall yield from L-serine benzyl ester, Compound 5 reacted cleanly with the sodium thiolate salt of a variety of unprotected 1-thio sugars in aqueous buffer to afford the corr esponding S-linked amino acid glycoconjugates in good yields after hydrolys is of the N-sulfates.