Cu-mediated Stille reactions of sterically congested fragments: towards the total synthesis of zoanthamine

A study on the Stille reaction of alkenyl iodides and stannanes with structural resemblance to retrosynthetic fragments of a projected total synthesis of the marine alkaloid zoanthamine was carried out. A range of reaction conditions was examined, and a protocol developed by Corey utilizing excess copper(I) chloride and lithium chloride was found to be most efficient. The methodology was successfully applied to join two major fragments of the zoanthamine skeleton.