1. Synthesis of Leucascandrolide A via a Spontaneous MacrolactolizationJ. Am. Chem. Soc. 2002, 124, 13670-13671Presented by Vijayarajan Devannah3/19/2013 Ying Wang, JelenaJanjic, Sergey A. Kozmin

2. About Professor Sergey A. Kozmin Education and Professional • 1991-1993 Undergraduate Research Assistant with Professor Irina P. Beletskaya Lomonosov Moscow State University, Moscow, Russia • 1993-1998 Graduate Research Assistant with Professor Viresh H. RawalUniversity of • Chicago, Chicago, Illinois • 1998-2000 Postdoctoral Associate with Professor Amos B. Smith, III University of Pennsylvania, Philadelphia, Pennsylvania • 2000-2006 Assistant Professor, University of Chicago • 2006-2011 Associate Professor, University of Chicago • 2011-present Professor, University of Chicago Notable Awards • 2003 Alfred P. Sloan Fellow • 2004 American Cancer Society Research Scholar • 2004 Amgen Young Investigator’s Award • 2004 Camille Dreyfus Teacher-Scholar Award • 2005 NSF CAREER Award • 2005 GlaxoSmithKline Chemistry Research Scholar

3. About Leucascandrolide A • Its is a highly bioactive marine macrolide isolated from new genus of calcerous sponges Leucascandra caveolata. • It displays potent cytotoxicity against KB and P388 tumor cell lines ( IC50 50 ng/ml and 0.25 μg/mL respectively), and it also a strong inhibitor of animal-pathogenic yeast candida albicans. Structural Features of Leucascandrolide A • It possess a 14 membered lactone • It includes dioxotricyclic core • It is highly unsaturated and contains oxazole in its side chain.

4. Retrosynthesis

5. Synthesis of C1-C15 Fragment Scheme 2 Scheme 3

6. Continues…… Scheme 4 Scheme 5

7. Formation of crucial Macrocycle Scheme 5

8. Synthesis of Oxazole side chain and completion of the target Leucascandrolide A Scheme 6

9. Conclusion • Racemic Leucascandrolide A was synthesized in longest linear sequence of 18 steps from commercially available precursors. 500 MHz 1H NMR and 125 MHz 13C NMR spectra of synthetic Leucascandrolide A was in excellent agreement with those reported in literature. • Total yield is 2%

10. Thank You