Synthesis, crystal structure determination, Hirshfeld surface and crystal void analyses, inter-action energy calculations and energy frameworks of (3aRS,4RS,9aRS)-2-benzyl-3-oxo-2,3,3a,4,9,9a-hexa-hydro-1H-benzo[f]iso-indole-4-carb-oxy-lic acid.

The title compound, C20H19NO3, consists of a benzyl moiety bonded to the nitro-gen atom of a 1H-benzo[f]iso-indole-4-carb-oxy-lic acid group. The fused pyrrole and cyclo-hexene rings of the iso-indole group are in envelope and flattened-boat conformations, respectively. The planar benzene rings are oriented at a dihedral angle of 69.64 (3)°. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules, enclosing R 2 2(14) and R 2 2(9) ring motifs, into infinite double-chains along the a-axis direction. π-π stacking inter-actions and C-H⋯π(ring) inter-actions help to consolidate the packing. Hirshfeld surface analysis revealed that the most important contributions for the crystal packing are from H⋯H (52.2%), H⋯C/C⋯H (24.0%) and H⋯O/O⋯H (21.2%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 92.25 Å3 and 11.52%, showing that there is no large cavity in the crystal packing. Computational methods revealed O-H⋯O and C-H⋯O hydrogen-bonding energies of -103.8, -82.2 and -35.5 kJ mol-1. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the electrostatic energy contributions.