An Efficient Synthesis of Ellipticine

Article abstract of DOI:10.1021/jo00135a034

A synthesis of the antitumor pyrido<4,3-b>carbazole alkaloid ellipticine (1a) is described in which the key steps are, successively, a highly regioselective acylation of 2-lithio-1-(phenylsulfonyl)indole (4) with 3,4-pyridinedicarboxylic anhydride (3) and acetic anhydride induced ring closure to give keto lactam 8.Further manipulation affords ellipticine in 54percent overall yield from indole (2a).