Water → (+/-)-Estra-4,9-diene-3,17-dione (Mixture of 2 EnantioMers)

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Reaction Conditions

Reaction Steps

A mixture of the products (III) and (IV) from example 18 (210.3 Mmoles) was slurried in 130 ml of dichloromethane and added over 30 minutes to a mixture of 103 ml of 96% sulfuric acid and 1.7 ml of 85% phosphoric acid which had been precooled to 2° C. The reaction was complete 90 minutes after the addition was finished. The mixture was added to 200 grams of ice and 100 ml of water; this was extracted with several portions of dichloromethane. The organic phase was concentrated to about 100 ml and 400 ml of isopropyl alcohol was added. This solution was concentrated to about 300 ml volume and cooled slowly to −20° C. The crystalline mass was filtered, washed with 2×30 ml of cold isopropanol and dried to give the product. The m.p. was 138.6-139.0° C., and the optical rotation [α]D=−132.5° (Cl, chloroform). NMR (CDCl3); 1.02 ppm (3H, s), 1.3-3.0 ppm, several multiplets, 5.70 ppm (1H, s).

Provenance & Evidence