反应详情

A suspension of 950 mg of 17-difluoromethylene-3-tetrahydropyranyloxy-estra-1,3,5(10),7-tetraene in 20 ml of methanol and 2.0 ml of water is refluxed with 950 mg of oxalic acid for 0.5 hour at a bath temperature of 100° C. Then, it is concentrated by evaporation in a vacuum diluted with ethyl acetate, washed with water, sodium bicarbonate solution as well as with saturated sodium chloride solution, dried on sodium sulfate, concentrated by evaporation in a vacuum and chromatographed on silica gel with hexane/ethyl acetate. 0.6 g of 17-difluoromethylene-estra-1,3,5(10),7-tetraen-3-ol is obtained as colorless crystals with a melting point of 126-129° C., [α]D22 =+163.7° (c=0.505% in pyridine)

1. concentrationThen, it is concentrated by evaporation in a vacuum
2. additiondiluted with ethyl acetate
3. washwashed with water, sodium bicarbonate solution as well as with saturated sodium chloride solution
4. customdried on sodium sulfate
5. concentrationconcentrated by evaporation in a vacuum
6. customchromatographed on silica gel with hexane/ethyl acetate