Facile zeolite induced Fischer-indole synthesis: a new approach to bioactive natural product rutaecarpine

Starting from glutaric anhydride () we have demonstrated an elegant six-step practical synthesis of bioactive natural product rutaecarpine () via o-amidoglutaranilic acid formation, esterification, chemoselective ester reduction, intramolecular dehydrative cyclizations, hydrazone formation and zeolite induced Fischer-indole synthesis with 53% overall yield. The conditions employed in the present synthesis are mild, efficient and general.