反应详情

温度

-78 °C

(R)-4-benzyloxazolidin-2-one 18 (212.6 mg, 1.19 mmol) was dissolved in dried 100 mL round-bottom flask containing anhydrous THF (8 mL) under N2 atmosphere. Cooled to −78° C. 2.5M solution of n-butyl lithium in hexanes (0.9 mL, 1.2 mmol) was added dropwise. Continuing the same temperature, 16 (2.4 mmol) was added to the reaction mixture and allowed to stir for 15 min. Then reaction mixture was warmed from −78° C. to 0° C. and allowed to stir for 30 min. The reaction mixture was quenched with aq. NH4Cl. The solvent was removed in vacuo, extracted with DCM and washed with brine, dried (MgSO4), filtered, and concentrated. The crude product was isolated by column chromatography eluting with (EtOAC/n-hexane, 20:80) to yield 19 (350 mg, 80%) as a brown semisolid. 1H NMR (CDCl3, 400 MHz) δ 2.77 (t, J=12 Hz, 1H), 3.29 (d, J=12.8 Hz, 1H), 4.23 (m, 2H), 4.35 (d, J=18.4 Hz, 1H), 4.47 (d, J=18.4 Hz, 1H), 4.67 (m, 1H), 7.16-7.30 (m, 7H), 7.40 (dd, J, =4 Hz, J2=2.4 Hz, 1H).

1. additionwas added to the reaction mixture
2. customThen reaction mixture
3. temperaturewas warmed from −78° C. to 0° C.
4. stirringto stir for 30 min
5. customThe reaction mixture was quenched with aq. NH4Cl
6. customThe solvent was removed in vacuo
7. extractionextracted with DCM
8. washwashed with brine
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. concentrationconcentrated
12. customThe crude product was isolated by column chromatography
13. washeluting with (EtOAC/n-hexane, 20:80)