5-Lanostene-7,11-dione

The structure of 7-meth-oxy-penta-cyclo-[5.4.0.02,6.03,10.05,9]undecane-8,11-dione, C12H12O3, at 150 K has monoclinic (P21/c) symmetry. The penta-cyclo-undecane cage compound is composed of four five-membered rings, a planar four-membered ring and a six-membered ring in a boat conformation fused into a closed strained-cage framework. All of the five-membered rings adopt an envelope conformation.

In the title compound, C19H17BrO3, the ring skeleton is located on a crystallographic mirror plane; two C atoms of the cyclo-hexene ring are disordered over the two locations to satisfy the preferred ring conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into chains along the a axis. π-π stacking inter-actions between benzo-quinone rings, with a centroid-centroid distance of 3.7225 (4) Å, are also observed, which connect the chains into a two-dimensional networkparallel to the ab plane.

The molecular structure of the title cyclophane, C20H18O4S, has two benzyl groups, a sulfone group, and two carbonyl groups adjacent to a double bond. The phenyl rings do not show intra-molecular stacking.