Stereodefined multisubstituted dienamides could be concisely prepared in high yields by directaddition of 1-lithiobutadiene derivatives to both N-aryl and N-alkyl isocyanates. Electrophiliccyclization of these dienamides was achieved to generate substituted cyclic iminoethers in excellentyields with perfect selectivity. When treated with 12 N aqueous HCl, dienamides underwent efficientand selective electrophilic cyclization to afford cyclic imidate derivatives. When treated with NBS,monobrominated or double-brominated cyclic iminoethers were formed.