A TfOH-catalyzed highly diastereoselective Michael addition/ketalization sequence of 3-hydroxyoxindoles and ortho-hydroxychalcones was developed, leading to biologically important bridged ketal spirooxindoles in moderate to excellent yields.
通过TfOH催化的高对映选择性Michael加成/
缩醛化序列,将3-羟基
吲哚和邻位-羟基
查尔酮进行反应,产生
生物重要的桥接
缩醛螺环
吲哚,收率在中等到优良之间。