Total Syntheses of ß-Carboline Alkaloids Manzamine C, Orthoscuticelline C, and Quassidine S.

ABSTRACT

A regioselective olefin hydrofunctionalization reaction of pavettine (4) with various nucleophiles was developed and used as the key step in the total syntheses of ß-carboline natural products manzamine C (3), orthoscuticelline C (5), and quassidine S (6). In the 6-step total synthesis of manzamine C (3), an efficient two-step procedure, comprising a Wittig olefination reaction and a Fukuyama-Mitsunobu reaction, was devised for the synthesis of the N-macrocycle with a Z-olefin.