ORGN 381 |
| Palau'amine (1), one of the oroidin-derived secondary metabolites, was isolated from the Belau sponge Stylotella aurantium by Kinnel and Scheuer in 1993. This complex, hexacyclic marine alkaloid contains a fully substituted chloro-cyclopentane ring, a piperazinone moiety and two cyclic guanidines. With the uniqueness and complexity of its structure, palau'amine has been a synthetic challenge and has not yet succumbed to total synthesis. We were able to construct the cyclopentane core containing every functionality and stereochemistry corresponding to the natural product, except the chloride stereochemistry (Org. Lett. 2005, 7, 1679; Tetrahedron 2006, 62, 5223). A pentacyclic compound having all but one ring system of palau'amine was synthesized from this core structure. The final cyclic guanidine would be constructed via C-H amination. Being a substructure of palau'amine, phakellin serves as a perfect model to test our key C-H amination reaction. Therefore the synthesis of phakellin (3) will also be discussed.
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Total Synthesis of Complex Molecules
1:00 PM-4:20 PM, Tuesday, March 27, 2007 McCormick Place East -- Room E352, Level 3, Oral
Division of Organic Chemistry |
