Our objective was to explore access to bicyclic tetrasubstituted olefins by rearrangement of large spirocyclic cations. Such olefins serve as precursors for subsequent photic conversion to domed bicyclic alkenes (betweenanenes). We synthesized the spirocyclic alcohol 13- hydroxyspiro-[12.11] tetracosane (14a) and dehydrated it under various acidic and non- acidic conditions to olefin mixtures containing these components: cyclo-dodecylidene- ...