Synthetic Approach to Tetrodotoxin

A novel and stereoselective approach to tetrodotoxin is described. The tricyclic compound having several key functional groups on the cyclohexane ring was synthesized from p-anisaldehyde with control of the four chiral centers. Iodoaminocyclization, 1,3-dipolar cycloaddition, and Baeyer-Villiger oxidation are the key steps of our approach.