An efficient method for the stereoselective synthesis of bicyclic azasugars with glycosidic heteroatom

A mild and effective method for the stereoselective synthesis of bicyclic azasugars with glycosidic heteroatom isdescribed. An SN2 reaction of D-ribose tosylate with amino alcohol or diamine followed by iminium formation and intramolecular N,X-acetak formation. As a result, a new class of bicyclic azasugars wherein the heteroatom is present at the glycosidic position through the intramolecular nucleophilic cyclization reaction without any catalyst were obtained in good to excellent yields with excellent stereoselectivity, and the desired products can be further derivatized to obtain more structural types of azasugars which act as the potential glucosidase inhibitors.