Synthesis of 5a-carba-hexopyranoses and hexopyranosylamines, as well as 5a,5a′-dicarbadisaccharides, from 3,8-dioxatricyclo[4.2.1.02,4]nonan-9-ol: glycosidase inhibitory activity of N-substituted 5a-carba-β-gluco- and β-galactopyranosylamines, and derivat

Since glycosidase and glycosyltransferase inhibitors, composed of carba-sugars, have recently attracted much attention, it is desirable to develop effective preparative routes for provision of new carba-sugar derivatives of potential biological interest. 1,2:3,6-Dianhydro-5a-carba-α-glucopyranose was here chosen for study of synthetic utility, and demonstrated to be a promising intermediate for supplying several carba-β-glycosylamines and N-linked dicarba-oligosaccharides. An N-linked 5a,5a′-dicarbalactose derivative obtained here was found to be a strong α-galactosidase inhibitor (IC50 1.2 μM, green coffee beans).