Design and synthesis of iso--DNJ and L-isoDALDP derivatives: pursuit of potent and selective inhibitors of α-glucosidase.

A series of iso--DNJ and L-isoDALDP derivatives were synthesized from dithioacetal 16 with sequential and highly diastereoselective Ho and Henry reactions, and aziridinium intermediate-mediated ring rearrangement as key steps. Glycosidase inhibition assay found four of them as selective α-glucosidase inhibitors, and the less substituted compound 30 showed more potent α-glucosidase inhibition (IC = 9.3 μM) than the others.