Synthesis of α-linked 3′-deoxy-cyclitol and -aminocyclitol glycosides

Unsaturated and saturated α-linked cyclitol and aminocyclitol glycosides have been prepared by a boron trifluoride–ether catalysed addition reaction of (3) and (4) to the appropriately functionalised cyclitol derivatives (2), followed by regiospecific hydrogenation from the β face; the structure and conformation of all products have been proved by 1H and 13C n.m.r. spectroscopy and chemical ionisation mass spectrometry.