ORGN 668 |
| Cyclopeptide alkaloids are natural products that have been isolated from the leaves, stem bark, root bark, and seeds of a wide variety of plant species throughout the world. To date, over two hundred structures have been described and these natural products have been shown to have numerous biological activities which include sedative, antibacterial, antifungal, and antiplasmodial effects. Their original structures, together with their restricted natural availability (0.0002–1% of dried plants), prompted immediate interest from the synthetic community. Primary synthetic challenges that must be overcome during their synthesis are: a) formation of the alkyl aryl ether or methylene linkage, b) installation of the enamide, and c) macrocyclization. Herein, we report a general strategy for the synthesis of cyclopeptide alkaloids that allowed for the preparation of natural products possessing different core structures such as paliurine F 1 (scheme 1) and abyssenine A 4 (scheme 2) and was used for the synthesis of a dozen of cyclopeptide alkaloids and analogues. The strategy used for the synthesis is depicted in Schemes 1 and 2 and features recently developed copper(I)-mediated coupling reactions for the installation of the key structural elements.
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Total Synthesis of Complex Molecules
8:00 AM-12:00 PM, Wednesday, August 22, 2007 BCEC -- 258A, Oral
Division of Organic Chemistry |
