This research is being supported by the Organic Synthesis Program. Dr. Hegedus will continue his development of transition metal based reagents as highly selective synthetic tools. The scientific significance of the research is that new chemical transformations of general use for organic synthesis will be developed, that new organic compounds with interesting physical, biological, and chemical properties will be produced, and that efficient synthetic approaches to a variety of heterocyclic and carbocyclic systems will be developed. The overall objective of the research is to develop new synthetic methods using transition metal complexes to permit new modes of reactivity for organic functional groups. This will be achieved by careful study of the fundamental chemistry of the metal-organic species involved, to permit the development of useful, new synthetic transformations. The newly developed processes will be applied to the synthesis of complex molecules when possible. Reactive organic intermediates such as electron-rich ketenes, chiral enamides, highly functionalized chiral quarternary centers, and "push-pull" allenes, will be made routinely accessible and usable for synthesis by generating them from metal complexes. The newly developed methodology will be used to synthesize the biologically active beta-lactam (+)-thienamycin, chiral tertiary alcohols for incorporation into macrocyclic antibiotics and polyether antibiotics, triquinanes and pyrroloindoloquinones.