title: Methyl (3S,3'R)-1-methyl-2,2''-dioxo-1',2',3',5',6',7',8',8a'-octa-hydro-dispiro-[indoline-3,2'-indolizine-3',3''-indoline]-1'-carboxyl-ate.
abstract: In the title compound, C(25)H(25)N(3)O(4), the central pyrrolidine ring and the two pyrrolidine rings adopt twisted conformations, whereas the piperidine ring in the octa-hydro-indolizine fused ring system adopts a chair conformation. The indoline ring systems are almost perpendicular with respect to the mean plane of the octa-hydro-indolizine ring system, making dihedral angles of 84.4 (5) and 79.4 (5)°. The acetate group attached to the octa-hydro-indolizine 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 inter-actions.
authors.affiliation: Department of Physics, S.M.K. Fomra Institute of Technology, Thaiyur, Chennai 603 103,  India.
authors.forename: G
authors.initials: G
authors.lastname: Ganesh
authors.forename: Panneer Selvam
authors.initials: PS
authors.lastname: Yuvaraj
authors.forename: E
authors.initials: E
authors.lastname: Govindan
authors.forename: Boreddy S R
authors.initials: BS
authors.lastname: Reddy
authors.forename: A
authors.initials: A
authors.lastname: Subbiahpandi