Preparation of a 1,2-isoxazolidine synthon for the synthesis of zetekitoxin AB.

A synthesis of the 1,2-isoxazolidine fragment of the potent voltage gated sodium channel blocker, zetekitoxin AB is described. The synthesis utilizes an intramolecular nitrone -olefin 1,3-dipolar cycloaddition to establish the stereochemistry of the cis-1,2-isoxazolidine. The oxidative cleavage of an all anti-triol with the excision of the central carbon is central to using α-D-glucopyranoside as a traceless stereochemical template. This route furnishes a suitably protected synthon for the synthesis of zetekitoxin AB.