Abstract
The first chapter describes the investigation into the application of the polyene cyclization process towards the generation of bridged and spiro bicycles. In the presence of Lewis acids, activated cyclohexenones substituted with a suitably tethered terminal olefin at the β’- position (i.e. 12 and 13) were found to cyclize to give bridged bicyclic compounds 15a. On the other hand, with the tether at the β- position (i.e. 19), spiro compounds 20 were obtained. Interestingly, in the cyclization reaction of 12 and 13, tricyclic compounds 14 and 15b were also isolated.The second chapter details the discovery of a novel access towards highly substituted bicyclic methylenecyclopentanes. The key process is an intramolecular cyclization of a β- positioned 3-butenyl appendage onto the activated α- carbon of the parent cycloalkanone. As such, in the presence of palladium acetate, cyano ketones 40-43 yielded bicyclic compounds 44-47 effectively and under essentially neutral conditions. This interesting access to polycyclic methyenecyclopentanes as well as the aforementioned polyene cyclization constitutes this thesis.