9320010 Williams The focus of this research is the develpoment of efficient, selective and practical methodolgy to construct alpha-amino acids in optically pure form, especially unsymmetrically substituted beta,beta-disubstituted and alkynyl amino acids. Efforts will be devoted to both methodology and total synthesis of complex amino acid-containing natural products. The main classes of methodology will include: 1) the Diels-Alder cycloaddition reactions to dehydroglycinates; 2) 3+2 azomethine ylide and 2+2 photocycloadditions to dehydroglycinates; and 3) aza-cyclopropylvinyl rearrangements and trapping. The total synthesis of the glycopeptide vancomycin will be completed. In addition, aldol strategies to access the congested hydroxy amino acid antibiotics altemicidin and paraherquamide A wiil be pursued. %%% With this award the Synthetic Organic Program is supporting the research of Dr. Robert M. Williams of the Department of Chemistry at the Colorado State University. Professor Williams will focus his work in the area of developing efficient, selective and practical methodology to construct unusual amino acids in optically pure form amd to demonstrate the utility of these methods by synthesizing several complex amino acid-containing natural products.
