Construction of the Azepinoindole Core Tricycle of the Stemona Alkaloids
摘要:
The azepinoindole substructure common to a number of Stemona alkaloids is constructed by employing a 7-endo radical cyclization of a readily available N-alkylated hydroindolone substrate. The indolone precursors are prepared via [1 + 4] cycloaddition between a vinyl isocyanate and either dimethoxycarbene or cyclohexylisocyanide.