反应详情

To a solution of ethyl (±)-4-(4-carboxy-1,3-oxazol-2-yl)-3-phenylbutanoate (500 mg, 1.65 mmole) in dry THF (8 mL) was added 4-methylmorpholine (0.22 mL, 1.99 mmole) then ethyl chloroformate (0.19 mL, 1.99 mmole) at 0° C. After 10 min, NaBH4 (249 mg, 6.59 mmole) was added all at once, then MeOH (8 mL) was added dropwise. After 30 min, the mixture was quenched with H2O (20 mL) and extracted with EtOAc (3×20 mL). The combined organic extracts were dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was chromatographed on silica gel (80% EtOAc/hexanes) to give the title compound (371 mg, 78%) as a yellow oil: MS (ES) m/e 290 (M+H)+.

1. customat 0° C
2. additionwas added dropwise
3. waitAfter 30 min
4. customthe mixture was quenched with H2O (20 mL)
5. extractionextracted with EtOAc (3×20 mL)
6. dry with materialThe combined organic extracts were dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residue was chromatographed on silica gel (80% EtOAc/hexanes)