ORGN 947 |
| In an effort to create new ways of synthesizing polycyclic highly valuable alkaloids, we have opted for the use of azomethine ylid in a cascade of reactions. This cascade takes advantage of our recently published (J. Org. Chem. 2006, 71, 704) Vilsmeier-Haack cyclization with tethered, non aromatic carbon nucleophiles as the cascade initiation step (1 to 3, depicted below). A subsequent deprotonation generates 1,3-dipole 4 that undergoes a [3+2] cycloaddition with electron-poor dipolarophiles. Depending on the relative arrangement of the functional groups in the starting material, the cascade generates fused, bridged or spiro ring systems, thus opening the way to the synthesis of a large variety of alkaloid skeletons. The development of the cascade, mechanistic aspects and opportunities toward total synthesis will be presented.
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New Reactions and Methodology
1:00 PM-5:00 PM, Thursday, 14 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |
