Unusual Natural Products: Lessons Learned in Pursuit of KS-504d and Curvulamine
This thesis details some of the paths taken, ideas explored, and failures met with during synthesis projects targeting two unusual natural products, neither of which has to-date succumbed to total synthesis. The first natural product, KS-504d, is a polychlorinated small molecule, possessing a chlorine-to-carbon ratio of greater-then-one. To contextualize the work and synthetic strategies, a brief background on chlorinated natural products and their synthesis is presented, followed by a discussion of KS-504d and the related family of natural products, along with similar halogenated small molecules. Initial exploratory studies - “information gathering”- are presented, followed by a discussion of a successful synthesis of a model system of KS-504d and unsuccessful attempts to translate this success to a total synthesis of the natural product.
The second natural product, curvulamine, is a pyrrole-containing natural product with a caged tricyclic core and a challenging stereochemical arrangement. The synthetic work is prefaced by a discussion of the natural product and the key structural features of the natural product. Syntheses of other natural products which possess similar structural features to curvulamine are presented along with an analysis of the strategies used to access those natural products. Our work is presented in such a way as to demonstrate the growth and refinement of our synthetic strategy, with multiple failed routes and undesired stereochemical outcomes eventually giving way to a successful synthesis of the stereochemically-rich central ring of the natural product as well as a tentative synthesis of the tricyclic core structure of curvulamine.