The preparation of 19-nor-5α-androstane 3β, 5, 17β-triol 3, 17 diacetate (10) is described. When this alcohol was treated with the mercuric oxide-iodine reagent it underwent fragmentation of the C (5)–C (10) bond with formation of a new type of 10-membered ring containing 5, 10-seco-steroidal compounds, ie (Z)-and (E)-19-nor-3β, 17β diacetoxy-5, 10- seco-androst-1 (10)-en-5-one (11 and 12), in 27 and 49% yield, respectively.
