Synthesis of L-fucopyranosyl-4-thiodisaccharides from levoglucosenone and their inhibitory activity on α-L-fucosidase

A new method of stereoselective synthesis of α-(1–4) linked thiodisaccharides: 4-S-(α-L-fucopyranosyl)-4-thio-3-deoxy-α-D-glucopyranose 6 and 2-acetamido-2,3-dideoxy-4-thio-(α-L-fucopyranosyl)-4-thio-α-D-glucopyranose 7, by Michael addition of 1-thio-α-L-fucopyranoside to levoglucosenone is described. The inhibition study of 6 and 7, against α-L-fucosidase (from bovine kidney) indicates the importance of 3-deoxy position of glucosamine moiety for total inhibitory effect Ki=4.0mM and Ki=2.4mM respectivelly.