Oxidative cyclization of ω-unsaturated O-alkyl hydroxamates: Studies toward the total asymmetric synthesis of alkaloid 235C

ORGN 739

Duncan J. Wardrop, wardropd@uic.edu, Maria V. Yermolina, myermo1@uic.edu, and Sarwat Chowdhury, sarwat@scripps.edu. Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Room 4500, Chicago, IL 60607-7061
Alkaloid 235C (3) is a novel dehydropumiliotoxin, which was detected as a trace alkaloid in the extracts of the Madagascan forest dwelling frogs Mantella aurantiaca and M. crocea. The structural novelty of 3 coupled with our interest in the application of heteroatom-stabilized nitrenium ions to organic synthesis, has recently led us to initiate a total synthesis of this target molecule. The key transformation in this endeavor involves the iodine(III)-promoted cyclization of allylsilane 1 to form dihydropyridinone 2. Details relating to the development and mechanism of this highly stereoselective nitrenium ion cyclization and our progress towards the total asymmetric synthesis of alkaloid 235C (3) will be presented.


Heterocycles and Aromatics, Asymmetric Reactions and Syntheses and Total Synthesis of Complex Molecules
7:00 PM-9:00 PM, Wednesday, August 19, 2009 Walter E. Washington Convention Center -- Ballroom C, Poster

8:00 PM-10:00 PM, Monday, August 17, 2009 Walter E. Washington Convention Center -- Hall D, Sci-Mix

Division of Organic Chemistry

The 238th ACS National Meeting, Washington, DC, August 16-20, 2009