反应详情

Triethylamine (1.3 mL, 9.1 mmol) was added to (S)-3-phenylbutyric acid (1.0 g, 6.1 mmol) in anhydrous tetrahydrofuran (60 mL) at −78° C. followed by the dropwise addition of pivaloyl chloride (0.83 ml, 6.7 mmol) to give a white solid. The reaction was allowed to warm to room temperature for 10 minutes then cooled back down to −78° C. In a separate flask, n-butyllithium (4.6 mL, 11.6 mmol, 2.5 M F in hexanes) was added to (S)-(+)-4-phenyl-2-oxazolidinone (2.0 g, 12.2 mmol) in anhydrous tetrahydrofuran at −78° C. and allowed to stir for 10 minutes. The lithiated oxazolidinone was transfered via cannula to the mixed anhydride at −78° C. and stirring continued for 2 hours. The reaction was quenched with water (25 mL) and extracted with ethyl acetate. The combined extracts were washed with water, brine and dried over sodium sulfate. The crude product was purified by chromatography over silica gel eluted with 2:3 ethyl acetate/hexanes and the resulting solid was recrystallized from ethyl acetate/hexanes to afford (S)-4-phenyl-3-((S)-3-phenyl-butyryl)-oxazolidin-2-one (1.63 g, 88% yield).

1. customto give a white solid
2. temperaturethen cooled back down to −78° C
3. stirringstirring
4. waitcontinued for 2 hours
5. customThe reaction was quenched with water (25 mL)
6. extractionextracted with ethyl acetate
7. washThe combined extracts were washed with water, brine
8. dry with materialdried over sodium sulfate
9. customThe crude product was purified by chromatography over silica gel
10. washeluted with 2:3 ethyl acetate/hexanes
11. customthe resulting solid was recrystallized from ethyl acetate/hexanes