Methanesulfonic Acid → Methyl 1-C-[4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl]-D-glucopyranoside

Participants

Reaction Conditions

Reaction Steps

To 4-bromo-1-chloro-2-(4-ethoxybenzyl)benzene (10 g, 0.031 mol) in anhydrous toluene/THF (78 mL, v/v=2:1) was added dropwise n-BuLi (2.5 M in hexane, 13.5 mL) at −65° C. and stirred for 30 minutes at −65° C. The mixture was transferred to a solution of (3R,4S,5R,6R)-3,4,5-tris(trimethylsilyloxy)-6-((trimethylsilyloxy)methyl)tetrahydro-2H-pyran-2-one (15.7 g, 0.034 mol) in toluene (78 mL) at −65° C. The mixture was stirred at −65° C. for 2 hours until starting material was consumed. The reaction was quenched with methanesulfonic acid (4.18 mL, 0.065 mol) in methanol (70 mL), and the mixture was allowed to warm to RT and stirred overnight. The reaction was quenched with saturated sodium bicarbonate, the organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with saturated bicarbonate, then with water, then with brine, and were dried over sodium sulfate. After removal of the volatiles, the residue was slurried in toluene/hexane (120 mL, 1:5), filtered, and dried under vacuum to give compound 4 as a white solid (12.5 g). The crude product was used in the next step without further purification.

Provenance & Evidence