反应详情

温度

0 °C

A 250-mL, round-bottomed flask, under an atmosphere of N2, was charged with sodium hydride (60% oil dispersion, 772 mg, 19.3 mmol). The sodium hydride was washed with 3 portions of hexanes to remove the oil and then 8 mL of anhydrous DMF was added followed by benzyl bromide (3.38 mL, 28.4 mmol). The solution was cooled to 0° C. and then a solution of methyl N-trityl-L-threoninate (4.83 g, 12.9 mmol) dissolved in 12 mL of DMF was added dropwise via cannula over 5 minutes. After stirring for 2 hours, the reaction mixture was treated with saturated aqueous Na2CO3 solution and 200 mL of Et2O and the layers were separated. The organic portion was washed successively with H2O (5×100 mL) and brine (100 mL), dried over MgSO4, filtered and concentrated under reduced pressure. Chromatography (SiO2, 5-10% ethyl acetate/hexanes) gave 4.61 g of methyl O-benzyl-N-trityl-L-threoninate as a colorless syrup.

1. washThe sodium hydride was washed with 3 portions of hexanes
2. customto remove the oil
3. addition8 mL of anhydrous DMF was added
4. additionwas added dropwise via cannula over 5 minutes
5. customthe layers were separated
6. washThe organic portion was washed successively with H2O (5×100 mL) and brine (100 mL)
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure