| Phomactins are well-known platelet-activating factor antagonists containing a unique bridged-heterocyclic skeleton. Inspired by the interest from the pharmaceutical industry and challenged by the skeleton complexity of the phomactins, several research groups devised a target-oriented synthesis of the phomactin family members. In this thesis, I developed a second generation approach to the syntheses of all members of the phomactin family through one intermediate. The key transformations like the intermolecular cyclohexadienone annulations reaction and the ring closing metathesis were extensively investigated and optimized. In addition, the main intermediate was either synthesized in an optically pure form via the Corey-Bakshi-Shibata reduction with ee more than 96% or resolved with the Sharpless epoxidation up to 99% ee. The syntheses of the main intermediates require the Horner-Wadsworth-Emmons olefination, Weinreb amide preparation, Wulff-Dotz cyclohexadienone annulation reaction, and the Grubbs ring closing metathesis. |
