Here, we report a synthesis of the lower half C21-C40 fragment of the shellfish toxin, azaspiracid-1. The C28-C 40 fragment was synthesized by a coupling between the C 28-C35 epoxide and the C36-C40 dithioacetal anion, followed by the HI-ring spiroaminal formation. An aldehyde corresponding to the C28-C40 fragment was then coupled with the C21-C27 allylic stannane by using InCl 3. Finally, the FG-ring was constructed by HF-pyridine to accomplish the synthesis of the suitably protected C21-C40 fragment.
ASJC Scopus subject areas