反应详情

50 ml of 50% NaOH solution and 456 mg (2 mmol) of benzyltriethylammonium chloride are added to a solution of 6.04 g (20 mmol) of (2S,3R)-2-bromo-3-hydroxybutyric acid p-methoxybenzylamide in 150 ml of methylene chloride. The two-phase mixture is stirred vigorously for 20 hours at room temperature. The organic layer is separated off and the aqueous phase is then extracted with methylene chloride. The combined methylene chloride solutions are dried and concentrated by evaporation. The resulting crude product is chromatographed over 40 times its weight of silica gel in the system methylene chloride/methanol (99:1). After crystallisation of the pure fractions from methylene chloride/diethyl ether/petroleum ether, the title compound, melting point 75°-76°, is obtained.

1. customThe organic layer is separated off
2. extractionthe aqueous phase is then extracted with methylene chloride
3. dry with materialThe combined methylene chloride solutions are dried
4. concentrationconcentrated by evaporation
5. customThe resulting crude product is chromatographed over 40 times its weight of silica gel in the system methylene chloride/methanol (99:1)
6. customAfter crystallisation of the pure fractions from methylene chloride/diethyl ether/petroleum ether