反应详情

To the compound (346 mg, 0.917 mmol) obtained in Example 178b were added ethanol (4 mL) and 2N aqueous sodium hydroxide solution (0.915 mL, 1.83 mmol), and the mixture was stirred overnight. The reaction mixture was concentrated under reduced pressure, and the residue was extracted with water, and washed with ether. The aqueous layer was acidified with 6N hydrochloric acid, and extracted with ethyl acetate. The extract was washed with saturated brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was recrystallized from ethyl acetate-hexane to give the title compound (237 mg, 71%) as colorless crystals.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. extractionthe residue was extracted with water
3. washwashed with ether
4. extractionextracted with ethyl acetate
5. washThe extract was washed with saturated brine
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was recrystallized from ethyl acetate-hexane