Cascade Cyclization Synthesis of Fused Polycyclic Ethers

Emory University, Atlanta GA

Investigators

Abstract

In this project funded by the Chemical Synthesis Program of the Chemistry Division, Prof. Frank E. McDonald of Emory University is developing the efficient preparation of structurally complex marine natural products, exemplified by brevenal, a non-toxic inhibitor of airborne toxins naturally produced by red tide events in tropical and subtropical marine regions, including the Gulf of Mexico. To decrease the large number of steps required to construct such structurally complex compounds, the research plan addresses this challenge by exploiting a new sequential cyclization strategy for the chemical synthesis of polycyclic ethers, with brevenal as the principal target structure. Broader impacts of this research include a collaborative exercise in which students, including those working on this project, improve their scientific communication skills to better explain to the general public what scientists do, and why what they do is important. Students make short presentations on an ongoing or recently completed research experience, directed to diverse audiences, including an educated adult non-scientist, and an elementary school-age child and receive feedback on presentations by peer students. In order to efficiently prepare fused polycyclic ether natural products, the Emory group is working to harness stereo- and regioselective cascades of ring-forming reactions. The proposed work shifts the paradigm of cascade cyclizations for fused polycyclic ether synthesis from a narrow focus on the difficult endo-mode polyepoxide cyclization, to other cascade cyclization approaches including the exo-mode oxacyclization strategy in this project. The proposed work includes exercises in improving scientific communication skills, both for students working on this project and for other students taking advanced coursework in chemistry.