7 alpha-Methylnorethindrone enanthate 10 beta-hydroperoxide: isolation and characterization

10 beta-Hydroperoxy-7 alpha-methylnorethindrone 17-heptanoate (II), a product of allylic autoxidation of 7 alpha-methylnorethindrone enanthate (I), has been isolated and characterized. The synthesis of the hydroperoxide (II) from the 3-ethylene ketal of 7 alpha-methylnorethynodrel (III) was achieved. Esterification of alcohol (III), subsequent deketalization, and photochemical oxygenation resulted in the hydroperoxide (II). Reduction of the hydroperoxide (II) to the 10 beta-alcohol (VI) and acetylation of (II) to the 10 beta-acetoxyperoxide (VII) are described. A single subcutaneous injection of the compounds (II), (VI), and (VII) to rats failed to produce long term inhibition of fertility in contrast to the parent compound (I) which is at least five times more effective than norethindrone enanthate as measured by suppression of vaginal cornification and estrous cycles.