Water → 9-Dehydroandrostenedione

関与物質

反応手順

9α-Hydroxyandrostenedione (5.00 g.) is dissolved in methylene chloride (50 ml.) and cooled to 0°-5°. A solution of chlorosulfonic acid (2.5 ml.) in methylene chloride (10 ml.) is added slowly over a period of 4 minutes. At the end of the addition TLC shows the reaction is completed. Water (60 ml.) is added to the reaction mixture keeping the temperature at 3°-15°. The mixture is stirred for 2 minutes and heptane (135 ml.) is added. The organic phase is separated and washed twice with water (30 ml. each time). The organic phase is concentrated with heat to about 30 ml. with crystals forming as the solution cools. The mixture is cooled to 0°-5°, filtered, washed with a minimum amount of heptane, and dried at 70° to give androsta-4,9(11)-diene-3,17-dione; 4.45 g. (89.0% weight yield, 94.7% chemical yield), m.p., 195.5°-202°; [α]D +220° (chloroform); UV (methanol) λmax =240 nm (ε=16,300).

情報源と証拠