Crystal structures of 2′-benzoyl-1′-(4-methylphenyl)-1,1′,2,2′,5′,6′,7′,7a′-octahydrospiro[indole-3,3′-pyrrolizin]-2-one and 2′-(4-bromobenzoyl)-1′-(2-chlorophenyl)-1,1′,2,2′,5′,6′,7′,7a′-octahydrospiro[indole-3,3′-pyrrolizin]-2-one

Abstract

The two title compounds, C28H26N2O2, (I), and C27H22BrClN2O2, (II), differ in their substituents, viz.4-methylphenyl and benzoyl rings in (I) replaced by 2-chlorophenyl and 4- bromobenzoyl, respectively, in (II). A significant difference between the two molecules 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 intermolecular C - H⋯O interactions. The chemical modifications in (I) and (II) do not seem to affect the type nor strength of the intermolecular N - H⋯N and C - H⋯O hydrogen bonds responsible for the two crystal structures, such that the aggregation of molecules appears similar in spite of the molecular changes.