Pyrano[3,2-b]indole derivatives 4, 5 and 8 have been synthesised in good yields from 1-acetyl-2-benzylidene-1H-indol-3(2H)-one 3 and 7 via an intramolecular Hetero Diels-Alder reaction with inverse electron demand.
1-acetyl-2-benzylidene-1H-indol-3(2H)-one 3 和 7 通过分子内异狄尔斯-阿尔德(Hetero Diels-Alder)反电子需求反应合成了
吡喃并[3,2-b]
吲哚衍
生物 4、5 和 8,产量良好。