Department of Chemistry, Columbia University , NewYork, New York 10027, United States.
J Am Chem Soc. 2014 Jul 16;136(28):9878-81. doi: 10.1021/ja505131v. Epub 2014 Jun 30.
An approach to the synthesis of the (iso)cyclocitrinol core structure is described. The key step is a tandem Ireland Claisen/Cope rearrangement sequence, wherein the Ireland Claisen rearrangement effects ring contraction to a strained 10-membered ring, and that strain in turn drives the Cope rearrangement under unusually mild thermal conditions. A major side product was identified as resulting from an unexpected and remarkably facile [1,3]-sigmatropic rearrangement, and a tactic to disfavor the [1,3] pathway and increase the efficiency of the tandem reaction was rationally devised.
描述了（异）环维林醇核心结构的合成方法。关键步骤是串联的爱尔兰克莱森/Cope 重排序列，其中爱尔兰克莱森重排使环收缩成一个应变的 10 元环，而这种应变反过来在异常温和的热条件下驱动 Cope 重排。一个主要的副产物被确定是由于一个意想不到的、非常容易的[1,3]-σ迁移重排而产生的，并且合理设计了一种策略来不利于[1,3]途径并提高串联反应的效率。
