Synthetic Studies Of Nicotine Analogues,Aominine And Vincorine

This thesis is mainly focused on the synthetic studies of the nicotine analogues, anonimine, and vincorine. It consists of three parts.The work presented in Part I was focused on the synthetic studies of the nicotine analogues. An azomethine-alkene [3+2] dipolar addition was designed as the key transformation for the construction of the tricylic system. Our synthesis commenced from pyridine. Vilsmeier-Haack reaction and Corey-Fuchs reaction were adopted for the preparation of the precursor of the azomethine-alkene [3+2] dipolar cycloaddition. However, the attempt of the key [3+2] dipolar cycloaddition was unsuccessful.Part II deals with synthetic studies towards indole alkaloid anominine. An intermolecular Micheal addition reaction and the subsequent intramolecular Ti(0)-mediated enyne cyclization were designed as the key transformations. So far, enone2-35, the key precursor of the Micheal addition, has been successfully prepared.The final part of this thesis involves the synthetic studies towards alkaloid vincorine. A key precursor for the total synthesis of vincorine has been synthesized form commercially available5-methoxytryptamine. Both intermolecular and intramolecular Diels-Alder reactions were tested for the construction of the polycyclic framework of this natural product. However neither of them led to the desired product.