5′′-(4-Methoxybenzylidene)-1′-(4-methoxyphenyl)-1′′-methyl-1′,2′,3′,5′,6′,7′,8′,8a′-octahydrodispiro[acenaphthylene-1,3′-indolizine-2′,3′′-piperidine]-2,4′′(1 H )-dione

In the title compound, C 39 H 38 N 2 O 4 , the pyridinone ring adopts a twisted half-chair conformation with the N atom deviating by 0.3304 (1) and with the methylene C atom adjacent to the octahydroindolizine unit deviating by 0.444 (3) Å from the mean plane defined by the other four atoms. In the octahydroindolizine system, the pyrrolidine ring exhibits an envelope conformation, with the fused methyne C atom deviating by 0.6315 (1) Å from the mean plane defined by the other four atoms, and the piperidine ring exhibits a distorted chair conformation, as reflected in the puckering parameters Q = 0.568 (4) Å, θ = 1.5 (4) and ϕ = 161 (16)°. In the crystal pairs of weak C—H...O interactions form centrosymmetric dimers, which are further connected by C—H...π interactions. The crystal studied was a non-merohedral twin, with a domain ratio of 0.91:0.09.