Acta Crystallographica Section E (Oct 2012)
Methyl (3S,3′R)-1-methyl-2,2′′-dioxo-1′,2′,3′,5′,6′,7′,8′,8a′-octahydrodispiro[indoline-3,2′-indolizine-3′,3′′-indoline]-1′-carboxylate
Abstract
In the title compound, C25H25N3O4, the central pyrrolidine ring and the two pyrrolidine rings adopt twisted conformations, whereas the piperidine ring in the octahydroindolizine fused ring system adopts a chair conformation. The indoline ring systems are almost perpendicular with respect to the mean plane of the octahydroindolizine ring system, making dihedral angles of 84.4 (5) and 79.4 (5)°. The acetate group attached to the octahydroindolizine ring system assumes an extended conformation. In the crystal, N—H...O hydrogen bonds result in the formation of a helical C(7) chain running parallel to [101]. The crystal packing features C—H...O hydrogen bonds and C—H...π interactions.