Abstract: During the course of a broad investigation of the intramolecular [4+ 21 cycloaddition reactions of enamines and enamides with unactivated butadienes, efforts were directed toward the construction of the spirocycles 10a and 10b which possess the molecular framework characteristic of the Erythrina alkaloids. Whereas it was not possible to prepare the requisite enamino diene 9a or the enamido diene 9b by the reaction of l- ...
