Novel Estrones by Oxidation of the Benzylic Positions of the Estrane Skeleton with tert‐Butyl Hydroperoxide and Cobalt Acetate

Four new estrone derivatives were isolated after treatment of estrone 3‐methyl ether (3‐methoxyestra‐1,3,5(10)‐trien‐17‐one (3) with tert‐butyl hydroperoxide and cobalt acetate. Three of the four steroidal compounds − the 9α‐(tert‐butylperoxy)‐6‐one 4, the 9α‐hydroxy‐6‐one 5, and the 9β‐hydroxy‐6‐one 7 − originated from oxidation at the 6‐ and 9‐positions. In contrast, oxidation of 3 to a 9β‐(tert‐butylperoxy) compound afforded the 8‐hydroxy‐9‐cyclodecanone derivative 6 through a molecular rearrangement involving the cleavage of the 8−9 bond. The structures of the compounds were secured by spectroscopic evidence including COSY, HSQC, and NOESY experiments combined with X‐ray crystallographic analysis and molecular modeling studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)