Crystal structures of 2'-benzoyl-1'-(4-methyl-phenyl)-1,1',2,2',5',6',7',7a'-octa-hydro-spiro-[indole-3,3'-pyrrolizin]-2-one and 2'-(4-bromo-benzoyl)-1'-(2-chloro-phen-yl)-1,1',2,2',5',6',7',7a'-octa-hydro-spiro-[indole-3,3'-pyrrolizin]-2-one.

The two title compounds, C28H26N2O2, (I), and C27H22BrClN2O2, (II), differ in their substituents, viz.4-methyl-phenyl and benzoyl rings in (I) replaced by 2-chloro-phenyl and 4- bromo-benzoyl, respectively, in (II). A significant difference between the two mol-ecules is found in the deviation of the benzoyl O atom from the least-squares plane of the ring to which it is attached [0.593 (4) and 0.131 (3) Å, respectively], a fact which may be attributed to the different participation of the benzoyl O atoms as acceptors in their inter-molecular C-H⋯O inter-actions. The chemical modifications in (I) and (II) do not seem to affect the type nor strength of the inter-molecular N-H⋯N and C-H⋯O hydrogen bonds responsible for the two crystal structures, such that the aggregation of mol-ecules appears similar in spite of the mol-ecular changes.