The crystal structures of 6′-(4-chlorophenyl)- and 6′-(4-methoxyphenyl)-6a′-nitro-6a′,6b′,7′,9′,10′,12a′-hexahydro-2H,6′H,8′H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one

Abstract

In the title compounds, C32H25ClN2O4 (I) and C33H28N2O5 (II), the six-membered pyran and piperidine rings adopt envelope and chair conformations, respectively. The five-membered pyrrolidine rings adopt twist conformations. Compound (II) crystallizes with two independent molecules (A and B) in the asymmetric unit. In all three molecules there is a C—H...O intramolecular hydrogen bond present enclosing an S(7) ring motif. In (I), both oxygen atoms of the nitro group are disordered, while in (II) the methoxybenzene group is disordered in molecule B. The geometries were regularized by soft restraints. In the crystal of (I), molecules are linked by C—H...O hydrogen bonds, forming chains along [010]. The chains are linked by C—H...Cl hydrogen bonds, forming layers parallel to (10\overline{1}). Within the layer there are C—H...π interactions present. In the crystal of (II), the A and B molecules are linked via C—H...O hydrogen bonds, forming a square four-membered A–B–A–B unit. These units are linked by a number of C—H...π interactions, forming a three-dimensional supramolecular structure.

Keywords

• crystal structure
• spiro compounds
• cycloaddition
• piperidine
• nitrogen-containing heterocycle
• pyran
• pyrrolidine
• hydrogen bonding