The focus of this research is the preparation of cyclopeptide alkaloids and astins. Methodology for the synthesis of 13, 14, and 16 membered ring systems will be developed and new ways of introducing the enamide bond will be compared. Various aspects of macrocyclization will be examined including the incorporation of psuedo-prolines into key sites in the molecules. Also, spectroscopic studies of the products will be carried out to probe the ability of the molecules to bind to metal cations. With this Renewal award, the Synthetic Organic Program is supporting the research of Dr. Madeleine M. Joullie of the Department of Chemistry at the University of Pennsylvania. Professor Joullie will focus her work on the synthesis of a series of cyclopeptide alkaloids that possess interesting biological and physical properties.