Boron trifluoride → (2S,3R,4R,5S,6R)-2-[3-(4-benzyl-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethyl)-4-chloro-phenyl]-6-hydroxymethyl-tetrahydro-pyran-3,4,5-triol

Participants

Reaction Steps

To a stirred solution of (2S,3R,4S,5S,6R)-2-[3-(4-benzyl-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethyl)-4-chloro-phenyl]-6-hydroxymethyl-2-methoxy-tetrahydro-pyran-3,4,5-triol (5.0 g, 9.24 mmol) in acetonitrile-dichloromethane mixture (1:1 mixture, 40 mL) was added boron trifluoride diethyletharate complex (2.34 mL, 18.48 mmol), and triethylsilane (5.95 mL, 36.9 mmol) at −10° C. After stirring for 4 h at the same temperature, the reaction was quenched with aq. saturated sodium bicarbonate solution (15 mL). The volatiles were evaporated under reduced pressure; the resulting mixture was extracted with dichloromethane (2×30 mL). The organic layer was washed with brine (10 mL), dried over sodium sulfate, concentrated and purified by preparative HPLC to furnish (2S,3R,4R,5S,6R)-2-[3-(4-benzyl-3,4-dihydro-2H-benzo[1,4]oxazin-6-ylmethyl)-4-chloro-phenyl]-6-hydroxymethyl-tetrahydro-pyran-3,4,5-triol (3.5 g).

Provenance & Evidence