1. Rychnovsky’s Formal Synthesis of Leucascandrolide A Presented by BriAnne Bentivegna March 19, 2013 University of Delaware Kopecky, D.J.; Rychnovsky, S.D. J. Am. Chem. Soc. 2001, 123, 8420

2. Scott D. Rychnovsky 1981 - B.A. from University of California at Berkeley 1986 - PH.D. from Columbia University 1987 - NIH Postdoctoral Fellow at Harvard University 1988 - Faculty member at the University of Minnesota 1995 - Professor of Chemistry at the University of California – Irvine Numerous Awards including Arthur C. Cope Scholar Award, Pfizer Research Award in Synthetic Organic Chemistry and National Science Foundation Presidential Young Investigator Award. Associate Editor for The Journal of Organic Chemistry Research interests include synthesis of rimocidin, phorboxazole A, epicalyxin F, and leucascandrolide A. 1

3. Leucascandrolide A First isolated by Pietra and coworkers in 1996 from the calcareous sponge Leucascandra caveolata along the east coast of New Caledonia Displays potent cytotoxic activity in vitro on human P388 (Leukemia) cancer cells as well as antifungal activity Synthesized by several groups including the Rychnovsky, Leighton and Kozmin groups 2 Dambrosio, M.; Guerriero, A.; Debitus, C.; Pietra, F. Helvetica Chimica Acta. 1996, 79, 51

4. Retrosynthesis 3 Noyori Hydrogenation Noyori Hydrogenation Yamaguchi-type Cyclization Aldol - Prins Coupling

5. Synthesis of Aldo-Prins Precursor #1 4 Noyori Hydrogenation

6. Synthesis of Aldo-Prins Precursor #2 5 Noyori Hydrogenation

7. Aldol-Prins Coupling 6

8. Synthesis of Leucascandrolide A Macrolide 7 Leucascandrolide A Macrolide Yamaguchi-type Cyclization

9. Final Steps via Leighton 8 Hornberger, K. R.; Hamblett, C. L.; Leighton, J. L. J. Am. Chem. Soc. 2000, 122, 12894 Leucascandrolide A!!! Horner-Wadsworth-Emmons

10. Conclusion Leucascandrolide A Macrolide synthesized in 23 steps Leucascandrolide A synthesized in 25 steps with the help of Leighton Questions? 9