Stereocontrolled synthesis of (−)-5,11-dideoxytetrodotoxin

Asymmetric synthesis of (−)-5,11-dideoxytetrodotoxin, an analog of puffer fish toxin, was accomplished from a common key intermediate through a novel hydroxylation at the C-8 position with neighboring group participation of trichloroacetamide, a highly stereoselective addition of acetylide as an equivalent of carboxylic acid, and a new guanidine synthesis from trichloroacetamide as key steps. This study presents the first asymmetric synthesis among tetrodotoxin and its analogs.