To a stirred solution of methyl 6-O-tert-butyldiphenylsilyl-2,3,4-tri-O-benzyl-β-D-glucopyranoside (800 mg, 1.71 mmol) in 8.55 mL of dry dichloromethane at −78° C. was added 2,6-di-tert-butyl-4-methyl pyridine (632 mg, 3.08 mmol) followed by triflic anhydride (345 μl, 2.05 mmol). After stirring 15 minutes at −78° C., the mixture was warmed to room temperature over 20 minutes, and then poured into a solution of saturated aqueous NaHCO, (20 mL) and extracted with ethyl acetate (50 mL). The organic layer was washed with saturated NaHCO3 (3×20 mL), saturated aqueous NaCl (1×20 mL), and dried over magnesium sulfate. Concentration provided crude target compound, which was used in the next step without further purification.
