In the title compound, C31H30N2O, the cis-fused cyclo-hexene and cyclo-octane rings adopt boat and boat-chair conformations, respectively. The essentially planar five-membered N-heterocyclic ring [r.m.s. deviation = 0.017 (1) Å] is cis- and trans-fused, respectively, with the cyclo-hexene and cyclo-octane rings. In the crystal, mol-ecules are linked into inversion dimers through pairs of weak C-H⋯O inter-actions.