反应详情

(4S)-4-Benzyl-3-[(5S)-5-(4-fluorophenyl)-5-hydroxypentanoyl]-1,3-oxazolidin-2-one (37.54 mmol) was dissolved in N,N-dimethylformamide (40 mL) and then imidazole (2.97 g, 43.6 mmol) and tert-butyldimethylsilyl chloride (6.12 g, 40.6 mmol) were added. The reaction was stirred at room temperature for 19 h, poured into 0.1 N hydrochloric acid (500 mL) and extracted with 1:1 ethyl acetate-hexane (500 mL). The organic layer was washed with water (2×500 mL), brine (300 mL), dried over sodium sulfate, filtered, and concentrated. The residue was purified by crystallization from methanol (55 mL) by heating to a light boil and cooling slowly to room temperature over 18 h. The crystals were filtered cold and washed with cold methanol (45 mL) to afford (4S)-4-benzyl-3-[(5S)-5-{[tert-butyl(dimethyl)silyl]oxy}-5-(4-fluorophenyl)pentanoyl]-1,3-oxazolidin-2-one (16.04 g, 88% yield) as a white crystalline solid; mp 87.6° C.; Rf 0.66 (1:2 ethyl acetate-hexane); 1H NMR (300 MHz, CDCl3) δ 7.36-7.18 (m, 7H), 6.99 (t, J=8.7 Hz, 2H), 4.69-4.61 (m, 2H), 4.18-4.13 (m, 2H), 3.27 (dd, J=13.5, 3.2 Hz, 1H), 2.96-2.89 (m, 2H), 2.73 (dd, J=13.5, 9.7 Hz, 1H), 1.82-1.63 (m, 4H), 0.88 (s, 9H), 0.04 (s, 3H), −0.15 (s, 3H) ppm; MS [M−OSi(CH3)2C(CH3)3]+354.0.

1. extractionextracted with 1:1 ethyl acetate-hexane (500 mL)
2. washThe organic layer was washed with water (2×500 mL), brine (300 mL)
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by crystallization from methanol (55 mL)
7. temperatureby heating to a light boil
8. temperaturecooling slowly to room temperature over 18 h
9. filtrationThe crystals were filtered cold
10. washwashed with cold methanol (45 mL)