反应详情

Methyl N-trityl-L-serinate (3.61 g, 10.0 mmol), prepared by the method of Baldwin, Tetrahedron, 49, pp. 6309-6330, (1993), was dissolved in 50 mL of CH2Cl2 followed by the addition of 25 mL of 50% aqueous NaOH solution. To the stirred mixture were added benzyltrimethylammonium chloride (186 mg, 1.00 mmol) and benzyl bromide (1.20 mL, 10.0 mmol). After stirring overnight, the mixture was treated with 100 mL of ice water. After all of the ice had melted, 100 mL of CH2Cl2 was added and the layers were separated. The aqueous portion was extracted with another 50 mL of CH2Cl2 and the combined organic layers were washed with H2O (2×100 mL) and brine (3×50 mL). The organic portion was dried over Na2SO4, filtered and concentrated. Chromatography (SiO2, 10-20% ethyl acetate/hexanes) gave 3.22 g of methyl O-benzyl-N-trityl-L-serinate as a colorless syrup.

1. customthe layers were separated
2. extractionThe aqueous portion was extracted with another 50 mL of CH2Cl2
3. washthe combined organic layers were washed with H2O (2×100 mL) and brine (3×50 mL)
4. dry with materialThe organic portion was dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated