The UV.‐isomerisation of 11‐oxo‐14β,17α‐pregnane 9 to the 11,19‐cyclo‐derivative 11 is described. In addition the Pb(OAc)4‐fragmentation of photoproduct 11 was investigated. 11 yielded besides the expected 11‐oxo‐19‐hydroxy‐pregnane 18 the novel 9,11‐seco‐11,19‐cyclosteroid 19. The structure of 19 was established by chemical transformations and subsequently confirmed by X‐ray analysis [2].