Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins
作者:Christiane Schultze、Bernd Schmidt
DOI:10.3762/bjoc.14.278
日期:——
conveniently accessible through a microwave-promoted tandem Claisen rearrangement/Wittig olefination/cyclization sequence. They serve as a versatile platform for the annellation of five- to seven-membered rings using ring-closing olefin metathesis (RCM). Furano-, pyrano-, oxepino- and azepinocoumarins were synthesized from the same set of precursors using Ru-catalyzed double bond isomerizations and RCM in a defined
可通过微波促进的串联克莱森重排/维蒂希烯化/环化序列方便地获得8-烯丙基香豆素。它们是使用闭环烯烃复分解(RCM)进行五元至七元环环合的通用平台。使用Ru催化的双键异构化和RCM按定义的顺序,从同一组前体中合成呋喃并,吡喃并,氧杂环丁烷和氮杂环庚烷香豆素。一类产品吡喃并[2,3-f]亚甲基-2,8-二酮无法通过丙烯酸酯的直接RCM获得,但可通过辅助串联催化RCM /烯丙基氧化序列从类似的烯丙基醚获得。