Oxalic Acid → HCID 15307279, compound

Participants

Reaction Steps

A suspension of 900 mg of 17-difluoromethylene-3-tetrahydropyranyloxy-estra-1,3,5(10),9(11)-tetraene in 19 ml of methanol and 1.9 ml of water is refluxed with 900 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 three times with water, once with 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. After crystallization from hexane, 0.5 g of 17-difluoromethylene-estra-1,3,5(10),9(11)-tetraen-3-ol is obtained as colorless crystals with a melting point of 134-135° C., [α]D22 =+89.6° (c=0.515% in pyridine).

Provenance & Evidence