The objectives of this research proposal have been divided into three sections. Part I deals with the completion of currently funded work on total synthesis of the antitumor antibiotic echinosporin. Part II is concerned with applications of the intramolecular Kondrat'eva pyridine synthesis to natural products such as the cytotoxic marine metabolite amphimedine and some momoterpenoid pyridine alkaloids. Part III of the proposal describes exploratory methodological studies of metal catalyzed intramolecular free radical cyclizations of Alpha,Alpha-dichloroesters and related compounds to produce highly functionalized ring systems. These synthetic studies will hopefully make available compounds with potential as antitumor agents.