Regioselective synthesis of 1-hydroxycarbazoles via anionic [4+2] cycloaddition of furoindolones: a short synthesis of murrayafoline-A

Suitably N-protected furoindolones react regioselectively with a variety of Michael acceptors in the presence of LDA to give 1-hydroxycarbazoles in a single-pot process and in good yields. The methodology has been applied to the synthesis of murrayafoline-A.