(3aR,4S,7R,7aS)-2-Phenyl-4-propyl-3a,4,7,7a-tetra-hydro-1H-4,7-epithio-iso-indole-1,3-dione 8-oxide.

In the tetra-hydro-isoindole moiety of the title compound, C(17)H(17)NO(3)S, the six-membered ring assumes a boat configuration and the -S=O group bridges the prow and stern of the boat. The phenyl ring is oriented at a dihedral angle of 83.2 (1)° with respect to the pyrrole ring. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. A weak C-H⋯π inter-action involving the phenyl ring is also found. The crystal studied was an inversion twin.