A New and Facile Synthesis of Rutaecarpine Alkaloids

Relevant rutaecarpine analogues (1a-d) have been synthesized efficiently from the ring opened beta-carboline derivatives (3a-d) as key intermediates. A unique one-pot reductive-cyclization as key reaction furnished the synthesis of rutaecarpine alkaloids in excellent yields. The key intermediates (3a-d) were prepared from tryptamine following acylation, Bischler-Napieralski cyclization, benzoylation, and oxidative cleavage of the exocyclic double bond. This new synthetic approach provides a facile access to rutaecarpine analogues with potent inhibitory effect on platelet aggregation.