Hydrogen Bromide → alpha-D-Glucopyranosyl bromide, tetraacetate

1,2,3,4,6-penta-O-acetyl-α-D-glucopyranose (1.0 g, 2.60 mmol) was dissolved in 20 mL of dichloromethane and 1.90 mL of hydrobromic acid (33% in acetic acid) at 0° C., and the reaction was stirred while warming to room temperature. TLC (40% ethyl acetate-hexane) after 18 h showed complete consumption of the starting material and formation of a higher running spot. The reaction was slowly diluted with saturated sodium bicarbonate (25 mL), extracted into dichloromethane (2×100 mL), dried over sodium sulfate, filtered and concentrated to afford 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide which was used without purification.