This proposal is to continue the long-term support which has been the major financial basis of the work on total synthesis and methodology which has been the main focus of our research at Columbia for many years. Our main goal has been to develop synthetic methods to achieve desired transformations in a way that would also control the regio- and stereochemistry of the process. Eventually, of course, these methods are applied to the total synthesis of biologically interesting molecules. Over the years the specific targets have covered many structural types, such as steroids, indole alkaloids, prostaglandins, etc. At present, and not surprisingly, a major effort is toward the stereocontrolled total synthesis of the anticancer taxol. We hope, naturally, that our contributions will extend, beyond whatever specific target, to long- lasting advances in synthetic methodology of some generality.