ORGN 160 |
| The tetracyclic indole alkaloid ellipticine has attracted much attention from chemists and the medical community because of its antitumor activity. Numerous synthetic approaches to ellipticine and its analogs have appeared in the literature. Our interest in ellipticine is related to a general synthetic strategy that is centered at elaboration of symmetical starting materials/intermediates to afford unsymmetrical natural products. For ellipticine we planned to derive the terminal pyridine ring from a cyclopentanone unit. Our work started from the known (symmetrical) 4,7-dimethylindan-2-one. From the 5-iodo derivative a Suzuki coupling with 2-nitrophenylboronic acid and subsequent cyclodeoxygenation on heating with triethyl phosphite achieved the construction of a tetracyclic system {a cyclopentanocarbazole). The final stage involved an oxidative insertion of a nitrogen atom to the terminal ring. Efforts to break the local symmetry around the ketone group is described. |
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Heterocycles, Aromatics, Materials, Devices, Switches, Combinatorial Chemistry, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, 13 March 2005 Convention Center -- Hall D, Poster
Division of Organic Chemistry |