反应详情

To an ice-cooled, stirred mixture of 3α-hydroxy-5α-pregnan-20-one (260 mg, 318.5 g/m, 0.82 mmol), triethylamine (0.17 mL), and 4-dimethylaminopyridine (DMAP catalytic, 10 mg, 122.17 g/m, 82 umol) dissolved in 17 mL of dry dichloromethane under a nitrogen atmosphere was added pentafluoropropionyl chloride (168 mg, 182.5 g/m 0.92 mmol). The reaction was stirred at 0° C. for 10 hours and then poured into 100 mL of 10% HCl and 200 mL of ether. The organic phase was washed once more with acid, twice with saturated sodium bicarbonate, and then dried over magnesium sulfate. After removal of solvent in vacuo, the crude product was purified by filtration through a bed of silica gel with hexane/ethyl acetate (15:35) elution. The product was isolated from the two earliest fractions (100 mL each) to give (330 mg, 464.5 g/m, 0.71 mmol, 87%).

1. stirringThe reaction was stirred at 0° C. for 10 hours
2. washThe organic phase was washed once more with acid, twice with saturated sodium bicarbonate
3. dry with materialdried over magnesium sulfate
4. customAfter removal of solvent in vacuo
5. filtrationthe crude product was purified by filtration through a bed of silica gel with hexane/ethyl acetate (15:35) elution
6. customThe product was isolated from the two earliest fractions (100 mL each)
7. customto give (330 mg, 464.5 g/m, 0.71 mmol, 87%)