Synthesis of Highly Substituted γ-Butyrolactones by a Gold-Catalyzed Cascade Reaction of Benzyl Esters
作者:Maria Camila Blanco Jaimes、Alexander Ahrens、Daniel Pflästerer、Matthias Rudolph、A. Stephen K. Hashmi
DOI:10.1002/chem.201402524
日期:2015.1.2
3‐butynoic acids in a gold‐catalyzed cyclization/rearrangement cascade reaction provided 3‐propargyl γ‐butyrolactones with the alkene and the carbonyl group not being conjugated. Crossover experiments showed that the formation of the new CC bond is an intermolecular process. Initially propargylic–benzylic esters were used, but alkyl‐substituted benzylic esters worked equally well. In the case of the propargylic–benzylic
在金催化的环化/重排级联反应中,可以轻松获得3-丁酸的苄基酯,使3-炔丙基γ-丁内酯与烯烃和羰基不共轭。交叉实验表明,新的C的形成C键是一个分子间过程。最初使用炔丙基-苄基酯,但烷基取代的苄基酯也同样有效。在炔丙基-苄基产物的情况下,用氧化铝对产物进行简单处理后,与羰基,烯烃和丙二烯共轭后,引发了两倍的互变异构化,转变为烯丙基取代的γ-丁内酯。合成步骤可以分步进行,也可以单锅级联反应进行,收率相近。即使在金催化剂的存在下,新的丙二烯仍保持完整。