A New Two Step Route to 1-Hydroxy-9H-3-Carbazolecarboxylic Acid Derivatives from 3-Formylindole. Application to the Synthesis of Mukonine.

Carbazole alkaloid mukonine 6b was prepared from 3-formylindole in three steps (32% overall yield). The key step was the base-promoted cyclization of a mixed anhydride of mono ester mono acid 5