Facile Approaches to 2-Deoxy-d-glucose and 2-Deoxy-α-d-glucopyranonucleosides from d-Glucal

Convenient and stereoselective methods for the preparation of 2-deoxy-d-glucose and purine 2-deoxy-α-d-glucopyranonucleosides were developed. Halogen-mediated O-glycosidation of d-glucal by bromine in MeOH followed by reductive removal of the halo group and hydrolysis of methoxy group by zinc in saturated aqueous sodium dihydrogen phosphate gave 2-deoxy-d-glucose. Treatment of 3,4,6-tri-O-acetyl-d-glucal with IBr and 2,6-dichloropurine based on haloetherification and subsequent reductive removal of iodine and deprotection allowed the isolation of purin-9-yl 2-deoxy-α-d-glucopyranonucleoside. Preparation of several purin-9-yl 2-deoxy-α-d-glucopyranoside derivatives is also reported. Their configuration was confirmed by single crystal X-ray analysis of the key intermediate 2,6-dichloro-9-(2-iodo-2-deoxy-α-d-glucopyranosyl)purine.