Relative Stereochemical Determination and Synthesis of the C17–C25 δ-Lactone Fragment of Hemicalide
作者:Etienne Fleury、Geoffroy Sorin、Elise Prost、Ange Pancrazi、François Sautel、Georges Massiot、Marie-Isabelle Lannou、Janick Ardisson
DOI:10.1021/jo302440a
日期:2013.2.1
relative isomers from 16 to 4. Concise syntheses of the four candidate diastereomers were achieved using a common strategy based on a Dias aldehyde allylation reaction, an intramolecular Horner–Wadsworth–Emmons olefination, and a dihydroxylation reaction. Finally, thorough NMR comparisons enabled us to deduce the relative stereochemistry of the C1–C17 fragment with high certainty.
Hemicalide是一种新颖的海洋代谢产物聚酮化合物,以独特的作用机理而著称。由于纯化物质的量不足,该天然产物已逃避了完整的立体化学分配。最近,我们已经通过合成C1-C13片段确定了C8-C13六边形的相对立体化学。目前,我们报告了C17–C25δ-内酯片段的分配。真实的hemicalide的NMR分析以及计算构象研究使我们可以将假定的相对异构体的数量从16个减少到4个。使用基于Dias醛烯丙基化反应的常见策略,即分子内Horner,可以实现四种候选非对映异构体的精确合成。 –Wadsworth–Emmons烯烃化和二羟基化反应。最后,