Selenium Dioxide → Exemestane

Beteiligte Stoffe

Reaktionsschritte

A mixture of 6-methylenandrost-4-ene-3,17-dione (0.50 g), selenium dioxide (0.50 g) and t-butylalcohol (200 ml) was heated to reflux under nitrogen for about 30 hours. The cooled solution was filtered and then evaporated to dryness under reduced pressure. The residue was taken up in ethyl acetate (100 ml), treated with charcoal and washed consecutively with water, ammonium sulfide solution, cold 17% ammonium hydroxide, cold dilute hydrochloric acid, water, dried with sodium sulfate and finally evaporated to dryness. The crude product was chromatographed as described in example 1 to yield 0.20 g of pure 6-methylenandrosta-1,4-diene-3,17-dione, m.p. 188°-191° C.

Herkunft & Nachweise