反应详情

温度

-40 °C

To a solution of (R)-4-benzyl-3-propionyloxazolidin-2-one (1.0 equiv.) in DCM (0.13 M) was added TiCl4 (1.0 equiv.) at −40° C. The mixture was stirred at −40° C. for 10 min (yellow suspension), then DIPEA (2.5 equiv.) was added (dark red solution) and stirred at 0° C. for 20 min. (R)-tert-butyl 4-formyl-2,2-dimethyloxazolidine-3-carboxylate (1.0 equiv.) in DCM (0.5 M) was then added dropwise and the resulting mixture was stirred for 1.5 hours. The reaction was quenched by the addition of aqueous ammonium chloride and the mixture was extracted with ethyl acetate. The organic phase was separated, washed with brine, dried with magnesium sulfate, filtered, and concentrated. The residue was purified via column chromatography eluting with ethyl acetate and hexanes (1:4) to give (R)-tert-butyl 4-((1R,2R)-3-((R)-4-benzyl-2-oxooxazolidin-3-yl)-1-hydroxy-2-methyl-3-oxopropyl)-2,2-dimethyloxazolidine-3-carboxylate as the major product (5:2) in 58% yield. LC/MS=363.3 (M+H-Boc), Rt=1.09 min.

1. additionwas then added dropwise
2. stirringthe resulting mixture was stirred for 1.5 hours
3. customThe reaction was quenched by the addition of aqueous ammonium chloride
4. extractionthe mixture was extracted with ethyl acetate
5. customThe organic phase was separated
6. washwashed with brine
7. dry with materialdried with magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified via column chromatography
11. washeluting with ethyl acetate and hexanes (1:4)