On epoxidation of estr-5(10)-ene-3,17-dione, the 5β,10β-epoxide is the major product. The mixture of epoxides was converted into 5,10β-dihydroxy-5α-estrane-3,17-dione, 10α- and 10β-hydroxyestr-4-ene-3,17-dione, and estrone. Due to the sensitivity of the products, 1H NMR was the best way to monitor the reaction pathway.