In our retrosynthetic analysis of palmerolide A, the installation of the dienamide functionality was planned at a late stage in the synthesis by a copper-catalyzed cross-coupling [5] between 3,3-dimethylacrylamide and an (E)-alkenyl iodide generated by Takai olefination of an aldehyde at C23. The formation of the 20-membered macrocyclic lactone was envisaged by ring-closing metathesis (RCM) involving an acrylate at C19 and a terminal alkene at C3. [6] We ...
