The focus of this research is the development of carbon-carbon bond making processes that use organophosphorus moieties to control stereochemistry. Design of the auxiliaries strives to maximize chirality transfer while allowing recycling of the chiral auxiliaries. Activation of cyclic dioxaphosphoranes by site-selective complexation with silyl cations will afford substituted 1,2-diols with high regio- and stereospecificity. Control of acyclic stereochemistry using a phosphoryl group in concert with the Mukaiyama-Michael reaction is planned and the unique metallation/alkylation chemistry of spirooxyphosphoranes will be probed for both theoretical as well as synthetic gain. %%% With this renewal award, the Synthetic Organic Program is supporting the research of Dr. Slayton A. Evans of the Department of Chemistry at the University of North Carolina, Chapel hill. Professor Evans will focus his work on projects that center on the design of new and versatile stereoselective carbon-carbon bond making strategies all of which use organophosphorus moieties to control the stereochemical course of the reactions.