To a solution of phenyl 2,3,4-tri-O-benzyl-1-thio-D-glucopyranoside (3) (1.09 g, 2.00 mmol) in DMF (10 ml) was added sodium hydride (60% in oil, 96 mg, 2.40 mmol), and the resulting mixture was stirred at room temperature for 15 min. The reaction mixture was cooled to 0° C. and 4-azido-3-chlorobenzyl bromide (592 mg, 2.40 mmol) was added, which was followed by stirring at room temperature for 4 hr. Water (30 ml) was added and the mixture was extracted twice with ethyl acetate. The organic layers were combined, washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure and the residue obtained was purified by silica gel column chromatography (eluent; hexane:ethyl acetate=5:1) to give phenyl 6-O-(4-azido-3-chlorobenzyl)-2,3,4-tri-O-benzyl-1-thio-D-glucopyranoside (4) (1.33 g, yield 94%) as slightly yellow crystals.
