反应详情

Sodium borohydride (0.56 g, 14.83 mmol, 1.5 equiv) was added in portions at 0° C. to a solution of compound 21 (3.9 g, 9.88 mmol, 1.0 equiv) in THF (50 mL) and ethanol (50 mL). The reaction mixture was stirred at room temperature overnight, when L/CMS indicated that the reaction was complete. The mixture was concentrated under reduced pressure and the residue was diluted with ethyl acetate (300 mL) and water (50 mL). 1 M aqueous HCl was added dropwise to quench the reaction. The layers were separated and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with saturated brine (500 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the crude compound 22 (4.0 g, >99% yield) as a pale-yellow oil. This material was used subsequently.

1. concentrationThe mixture was concentrated under reduced pressure
2. additionthe residue was diluted with ethyl acetate (300 mL) and water (50 mL)
3. addition1 M aqueous HCl was added dropwise
4. customto quench
5. customthe reaction
6. customThe layers were separated
7. extractionthe aqueous layer was extracted with ethyl acetate (2×100 mL)
8. washThe combined organic layers were washed with saturated brine (500 mL)
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure