反应详情

A borane-tetrahydrofuran complex (0.93 M tetrahydrofuran solution) (375 ml, 0.35 mol) was added to a tetrahydrofuran (200 ml) solution of the compound (20 g, 86.8 mmol) obtained in Step 2 above under ice cooling and then the resulting mixture was heated to reflux for 19 hours. Methanol (130 ml) was added to the reaction mixture under ice cooling, the resulting mixture was stirred for 60 minutes and then the solvent was concentrated under reduced pressure. Ethanol (450 ml), water (150 ml), and triethylamine (150 ml) were added to the residue obtained, the resulting mixture was heated to reflux for 2 hours and then the solvent was concentrated under reduced pressure. The residue obtained was diluted with ethyl acetate, washed with saturated aqueous sodium bicarbonate solution and saturated brine, and then dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure and the residue obtained was purified by silica gel column chromatography [chloroform:methanol=10:1 (v/v)] to give the title compound (10.4 g, 59%) as a colorless oil.

1. temperaturethe resulting mixture was heated
2. temperatureto reflux for 19 hours
3. concentrationthe solvent was concentrated under reduced pressure
4. additionEthanol (450 ml), water (150 ml), and triethylamine (150 ml) were added to the residue
5. customobtained
6. temperaturethe resulting mixture was heated
7. temperatureto reflux for 2 hours
8. concentrationthe solvent was concentrated under reduced pressure
9. customThe residue obtained
10. washwashed with saturated aqueous sodium bicarbonate solution and saturated brine
11. dry with materialdried over anhydrous sodium sulfate
12. customThe solvent was evaporated under reduced pressure
13. customthe residue obtained
14. customwas purified by silica gel column chromatography [chloroform:methanol=10:1 (v/v)]