The focus of this research is the development of synthetic techniques for the preparation of alpha-amino acids. The main classes of methodology to be explored include: 1) allyl and crotyl silane/stannane additions to oxazinal-based oxonium ions to access hydroxymethylene peptide isostere; 2) an asymmetric (1,3) dipolar cycloaddition approach to spirotryprostatin; 3) unsymmetrically beta, beta-disubstituted alpha-amino acids via inter- and intramolecular SN2' reactions and via radical additions to E- and Z-alpha, beta-dehydro oxazinones; 4) preparation of Z-beta, gamma-unsaturated-alpha-amino acids and Z-1-aminocyclopropanecarboxylic acids. With this renewal award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Robert M. Williams of the Department of Chemistry at Colorado State University. Professor Williams will focus his work on developing efficient, selective and practical methodology for the construction of biologically important alpha-amino acids and their derivatives in optically pure form.