反应详情

(5R, 6S)-N-(5-Methanesulfonyloxy-2,2-dimethyl-1,3-dioxepan-6-yl)-3-acetoxy-2-methylbenzamide (compound [9], 34.2 g, 82.3 mmol) was dissolved in dichloromethane (340 ml) and boron trifluoride-diethyl ether complex (30.4 ml, 247 mmol) was added over 5 minutes with stirring at room temperature. The mixture was stirred for 40 hours at room temperature. Triethylamine (34.5 ml, 247 mmol) was added at not more than 15° C. and the solvent was distilled away under reduced pressure to ⅕ volume. The residue was diluted with ethyl acetate (340 ml) and washed successively with 10% brine (340 ml), 10% brine (340 ml) containing citric acid (17 g), and saturated brine (340 ml). After drying over magnesium sulfate, the solution was concentrated to 36 g to give a crude product of (2R)-2-methanesulfonyloxy-2-((4S)-2-(3-acetoxy-2-methylphenyl)-4,5-dihydrooxazol-4-yl)ethanol (compound [10]).

1. additionboron trifluoride-diethyl ether complex (30.4 ml, 247 mmol) was added over 5 minutes
2. stirringThe mixture was stirred for 40 hours at room temperature
3. distillationthe solvent was distilled away under reduced pressure
4. additionThe residue was diluted with ethyl acetate (340 ml)
5. washwashed successively with 10% brine (340 ml), 10% brine (340 ml)
6. additioncontaining citric acid (17 g), and saturated brine (340 ml)
7. dry with materialAfter drying over magnesium sulfate
8. concentrationthe solution was concentrated to 36 g