The focus of this research is efficient synthetic methodology based on the use of novel carbanions mainly produced by reduction of either small-ring oxygen heterocycles or of functionalized molecules containing the phenylthio group. A major emphasis is the production and use of lithioalkenes, but oxygenated organolithiums will also be used. Most of the methods involve the synthesis or modification of ring compounds with an emphasis being on ring compounds found in natural products. A highly novel investigation involves the copolymerization of butadiene and isoprene to a living polymer. %%% With this award, the Synthetic Organic Program is supporting the research of Dr. Theodore Cohen of the Department of Chemistry at the University of Pittsburgh. Professor Cohen will focus his work on the use of novel carbanions as intermediates in organic synthesis, mainly for the preparation or modification of cyclic compounds.