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 (2R,3R)-2-bromo-3-hydroxybutyric acid p-methoxybenzylamide in 150 ml of methylene chloride. The two phase mixture is vigorously stirred for 20 hours at room temperature. The organic layer is separated off and the aqueous phase is subsequently extracted with methylene chloride. The combined methylene chloride solutions are dried and concentrated by evaporation. The crude product that forms is chromatographed over 40 times the amount by weight of silica gel in a methylene chloride/methanol - 99:1 system. After crystallisation of the pure fractions from methylene chloride/ether/petroleum ether, the title compound is obtained, melting point 75°-76°.

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