反应详情

A suspension of 1.2 g of 17-difluoromethylene-11β-methoxy-3-tetrahydropyranyloxy-estra-1,3,5(10)-triene in 25 ml of methanol and 2.6 ml of water is refluxed with 1.2 g 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/acetone. After crystallization from hexane, 0.9 g of 17-difluoromethylene-11β-methoxy-estra-1,3,5(10)-trien-3-ol is obtained as colorless crystals with a melting point of 245-247° C., [α]D22 =+77.30 (c=0.535% 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/acetone
7. customAfter crystallization from hexane