(+)-Euryfuran cycloadds regiospecifically to activated monosubstituted 1,4-benzoquinones under mild conditions to give the corresponding Michael adducts which, depending on the quinone substituent, undergo in situ redox reactions to the respective euryfurylbenzoquinones. One of the reported Michael adducts undergoes a facile stereoselective cyclisation under oxidant conditions to afford a naphthofuro[4,3-c]benzopyran derivative. The regiospecificity of the Michael and cyclisation reactions are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.
(+)-白果
榄香烯在温和条件下区域选择性地与活化过的单取代1,4-苯醌发生环加成反应,生成相应的迈克尔加成物。这些加成物根据苯醌上的取代基在原位发生氧化还原反应,转化为相应的白果
榄香烯基苯醌。其中一种报告的迈克尔加成物在氧化条件下发生一个简单的立体选择性环化,生成一个
萘氧杂
环己烷[4,3-c]苯并
吡喃衍
生物。分别讨论了迈克尔加成和环化反应的区域选择性。(C) 2000 伊来克ipeCISION科学有限公司。所有权利保留。