Synthesis of thiodisaccharides related to 4-thiolactose. Specific structural modifications increase the inhibitory activity against β-galactosidase.

In the search for new glycosidase inhibitors, a set of benzyl β-D-Gal--(1→4)-3-deoxy-4-thio-α-D-hexopyranosides was synthesized. Diverse configurations were installed at C-2 and C-4 of the glucose residue. The benzyl glycosidic group was kept intact or substituted by an electron-donating or electron-withdrawing group that could also participate in hydrogen bonding.