Synthesis of Polysubstituted γ‐Butenolides via a Radical Pathway: Cyclization of α‐Bromo Aluminium Acetals and Comparison with the Cyclization of α‐Bromoesters at High Temperature
作者:Romain Bénéteau、Carole F. Despiau、Jean‐Christophe Rouaud、Anne Boussonnière、Virginie Silvestre、Jacques Lebreton、Fabrice Dénès
DOI:10.1002/chem.201501294
日期:2015.8.3
α‐bromoesters derived from propargyl alcohols by a one‐pot reaction involving the radical cyclization of α‐bromo aluminium acetals, followed by the oxidation of the resulting cyclic aluminium acetals in an Oppenauer‐type process and migration of the exocyclic CC bond into the α,β‐position. Comparison with the direct cyclization of α‐bromoesters at high temperature and under high dilution conditions is described
通过一锅反应,从α-溴铝缩醛进行自由基环化,然后通过Oppnauauer型工艺氧化生成的环状缩醛铝,可以从炔丙基醇衍生的α-溴酸酯中以高收率获得高收率的多取代丁烯内酯。和环外CC键迁移到α,β-位 描述了在高温和高稀释条件下与α-溴代酸酯直接环化的比较。氘标记实验使我们能够发现在这些环化过程中发生的“不可见的” 1,5-氢原子转移(1,5-HAT),以及后者在立体异构中心的差向异构化中的后果。与经典方法相比,厚朴(Plgiomnium undulatum)和来自黄斑狼疮(Kyrtuhrix maculans)。