Synthesis of (+)-Gonyautoxin 3

Significance

Gonyautoxin, saxitoxin and neosaxitoxin are the major constituents of para­lytic shellfish poisons. They inhibit electrical conduction in cells by acting as a stopper in ion flux through voltage-gated Na⁺ channels. The first asymmetric synthesis of gonyautoxin 3 (GTX 3) features a rhodium-catalyzed amination reaction (D → E) to access the tricyclic core of the toxin which is found in more than thirty natural products.