Polyquinane

A polyquinane polycyclic compound consisting of fused five-membered hydrocarbon rings.¹ If the compound is unsaturated instead of saturated, it is called a polyquinene. The simplest polyquinane is the bicyclic compound bicyclo[3.3.0]octane. Other members are triquinacene and dodecahedrane.

The compound triquinacene, sometimes simply called quinacene (tricyclo[5.2.1.0^4,10]deca-2,5,8-triene) is the second member of a family of polyquinenes. It was synthesized in 1964 in the group of R. B. Woodward² in connection with its suspected homoaromatic properties—though it was found to have no such properties—and also as part of a failed attempt to synthesize the then-elusive compound dodecahedrane. Triquinacene is stable, and has a melting point of 18 °C. The final step of its synthesis is a double Cope reaction to form two of the three alkenes.