Synthesis of functionalised β-lactones via silylcarbocyclisation/desilylation reactions of propargyl alcohols
作者:Laura Antonella Aronica、Caterina Mazzoni、Anna Maria Caporusso
DOI:10.1016/j.tet.2009.10.112
日期:2010.1
alkynol characterised by two alkyl groups on the propargyl carbon atom, significant amounts of the aldehydes were observed for secondary alcohols. In these cases, the use of ortho-substituted arylsilanes improved the chemoselectivity towards the α-methylene-β-lactones. Such molecules were then successfully converted into α-methylaryl-β-lactones by a fluoride-induced rearrangement of the aryl group that migrates
通过有效的铑催化的甲硅烷基碳环化反应,从炔丙基醇开始制备官能化的β-内酯。使用DBU作为碱,位阻醇和/或氢硅烷,可以高收率和完全的立体选择性进行此过程。否则,发生甲硅烷基甲酰化竞争反应,得到具有完全区域选择性的3-羟基-2-[(芳基二甲基甲硅烷基)亚甲基]烷基。确实,尽管α-(芳基二甲基甲硅烷基亚甲基)-β-内酯仅从炔丙基碳原子上具有两个烷基的炔醇开始生成,但对于仲醇却观察到大量的醛。在这些情况下,使用邻位取代的芳基硅烷改善了对α-亚甲基-β-内酯的化学选择性。然后,这些分子通过氟化物诱导的芳基的重排成功地转化为α-甲基芳基-β-内酯,芳基从硅迁移到碳并保留构型。