The Lyconadins: Enantioselective Total Syntheses of (+)-Lyconadin A and (−)-Lyconadin B
作者:Douglas C. Beshore、Amos B. Smith
DOI:10.1021/ja804939r
日期:2008.10.15
(+)-lyconadin A (1) and (-)-lyconadin B (2) is presented. Central to this venture was recognition and deployment of a key strategy-level intramolecular aldol/conjugate addition cascade that led, in a single operation, to two new carbon-carbon sigma-bonds, three new stereogenic centers, and two new rings, albeit with the incorrect stereogenicity at C(12) for the lyconadins. Correction of the C(12) stereogenicity
全面介绍了 (+)-lyconadin A (1) 和 (-)-lyconadin B (2) 的对映选择性全合成。该项目的核心是识别和部署一个关键的战略级分子内醛醇/共轭加成级联,在一次操作中,导致了两个新的碳碳 sigma 键、三个新的立体中心和两个新环,尽管lyconadins 在 C(12) 处的不正确立体性。C(12) 立体性的校正是通过质子化分子内胺的创新使用实现的。氨基碘烯烃环化结合 α-吡啶酮和 3,4-二氢吡啶酮环化方案,分别允许完成 (+)-lyconadin A (1) 和 (-)-lyconadin B (2) 的合成。