BIOMIMETIC TOTAL SYNTHESIS OF POLYCITRIN A

The synthesis of the marine alkaloid polycitrin A (1a) is described The synthesis is based on the formation of 3,4-bisarylpyrrole-2,5-dicarboxytic acids from 3-arylpyruvic acids by oxidative coupling and consecutive pyrrole ring formation. The pyrrole dicarboxylic acids are then converted into 3,4-bisaryl maleimides by treatment with hypochlorite. The synthesis is completed by bromination and introduction of the N-alkyl substituent. 1a is thus obtained in 6 steps from 3-(4-methoxyphenyl)pyruvic acid (6) with 26% overall yield.