The specific aims of this project (which have been sponsored by the NIH under grants A1 19133-06 and GM 31256-11, both three years each) include the consolidation of these grants into one grant of four year duration. In addition, and more importantly, we wish to develop a number of total syntheses using technology we have been in the process of developing for several years. The method centers around the use of vinylogous urethanes as four- carbon-synthons in both the aldol and acylation condensations. These four carbon synthons provide, by virtue of their rich functionality and their twisted geometries, several powerful synthetic advantages, relative to other enolate systems, in both the aldol and acylation reaction modes. We hope to demonstrate these advantages within the context of several different total syntheses, each designed to feature one or another virtue of these interesting and novel enolates. Lastly, we propose several different approaches towards a better mechanistic understanding of how these enolate systems work. We demonstrate some very fruitful collaborative work with Professor Paul Wllliard, and propose further X-ray experiments to answer interesting and exciting new questions that have been raised about these enolate systems and their derivatives during the course of this work.