Intramolecular cyclization strategies toward the synthesis of zoanthamine alkaloids

Stabilized 2-amino-1,3-dienes can participate in intramolecular Diels–Alder (IMDA) reactions with pendant dienophiles. We found that these dienes can be readily prepared via standard palladium-mediated coupling reactions and have comparable reactivity to 2-oxodienes. Application of these substrates to the synthesis of tetracyclic model systems representing the ABCE motif of the zoanthamines is presented.