作者:Itai Massad、Ilan Marek
DOI:10.1002/anie.202105834
日期:2021.8.16
transformation. Herein, we show that the key allylic vinyl acetals can be efficiently generated through alkene isomerization of their readily available regioisomeric counterparts (derived from allylic alcohols and α,β-unsaturated aldehydes), thus enabling the first systematic study of the substrate scope of this rearrangement, as well as the discovery of exceptionally mild conditions for its mediation by Lewis
Coates 在近四十年前首次研究了烯丙基乙烯基缩醛的 [3,3]-σ 重排,由于产品中具有多功能的单保护 1,5-二羰基基序,它与克莱森重排的其他变体有所不同。不幸的是,迄今为止,底物的合成难以捉摸的性质阻碍了这种有吸引力的转化的广泛应用。在此,我们表明,关键的烯丙基乙烯基缩醛可以通过其容易获得的区域异构对应物(衍生自烯丙醇和α,β-不饱和醛)的烯烃异构化来有效地生成,从而使得能够首次系统地研究这种重排的底物范围,以及发现路易斯酸和布朗斯台德酸介导其极其温和的条件。