Synthesis of fused tricyclic systems by thermal Cope rearrangement of furan-substituted vinyl cyclopropanes
作者:Verena Klaus、Stéphane Wittmann、Hans M. Senn、J. Stephen Clark
DOI:10.1039/c8ob00924d
日期:——
A novel method for the stereoselective construction of hexahydroazuleno[4,5-b]furans from simple precursors has been developed. The route involves the use of our recently developed Brønsted acid catalysed cyclisation reaction of acyclic ynenones to prepare fused 1-furanyl-2-alkenylcyclopropanes that undergo highly stereoselective thermal Cope rearrangement to produce fused tricyclic products. Substrates
已经开发了一种从简单的前体立体选择性构建六氢azuleno [4,5- b ]呋喃的新方法。该路线涉及使用我们最近开发的布朗斯台德酸催化的无环炔烃的环化反应,以制备稠合的1-呋喃基-2-烯基环丙烷,并对其进行高度立体选择性的热应对,从而产生稠合的三环产物。具有E-烯烃的底物在40°C时发生平滑的Cope重排,而相应的Z-异构体在此温度下不发生反应。已经进行了计算研究以解释在Cope重排反应中E-和Z-异构体的行为差异。hexahydroazuleno [4,5-[b ]由Cope重排产生的呋喃有潜力作为先进的中间体来合成愈创木酚内酯家族的天然产物。