This award supports cooperative research in the chemistry of carbon-bond seven-membered ring formation to be carried out by Rudolph Abramovitch of Clemson University and J.A.R. Rodriguez of the University of Campinas in Brazil. A new method of formation of seven-membered rings, previously discovered by the collaborators, will be extended to the production of homo- and hetero-cyclic rings to determine the structural and geometrical factors which favor ring formation. Then, convenient routes to molecules related to naturally-occurring anticancer agents will be examined. This will lead to the preparation of a variety of derivatives which retain useful biological activity but with reduced toxicity. The objective is to develop mild, useful routes to desirable biologically active compounds. This work is a continuation of a productive cooperation between the group at Campinas, a former member of which is now at Sao Paulo establishing a graduate program with eighteen research students, and Dr. Abramovitch's group at Clemson. The Brazilian P.I. and a student have both spent time at Clemson which has helped in the establishment of a small research group at Campinas now working on arylnitrenium ion chemistry. This study will increase the knowledge of the formation, structure and reactivity of arylnitrenium and -oxenium ions and bond formation in seven-membered rings which occur widely in nature and have been the target of much scientific and medicinal attention.
