Abstract: | In the title compound, pentacyclo11.8.1.13,11.07,23.015,20]tricosa‐3,5,7,9,11(23),15,17,19‐octaen‐22‐one, C23H20O, the bicyclo5.4.1]dodecan‐12‐one moiety takes a rigid conformation in which the seven‐ and eight‐membered rings take chair and boat–boat forms, respectively. The molecule has a non‐crystallographic mirror symmetry perpendicular to the benzene and naphthalene planes. |