Several investigations of reactions of enamines with acetylenedicarboxylates, leading to linear dieaamines via cyclobutene containing intermediates, have been reported. examples are known-in which the enamine moiety is acyclic,' part of a viclnyl endiamine group,2 and in which the eneportion is contained within a medium-ring system.3 As part of an effort directed at new synthetic 2 02CH3 I iN C02CH3 n -\ C02CH3 applications of N-vinyl-1,2-dihydropyridines and N-vinyl-2-pyridones, 4 we have investigated the reaction of dimethyl acetylene dicarboxylate with N-trans-&styryl-1,2_dihydropyridine (1). This ambident trienamine contains several reaction sites for both 2+2' and 4+26 cycloaddition by the acetylene derivative. Ae a result, reactions of N-vinyl-1,2-dihydropyridines with acetylene derivatives have the potential of yielding N-vinyldihydroazocines, such as 2 and 3, N-butadienyl-1,2dihydropyridines, ft, and or the interesting N-vinyl-L-azabicyclo[2.2.2]octa-4,7_dienes, 5. In view of this, the observation of a regioselectlve and efficient reaction leading to the N-styryldihydroazocine 6 from 1 and dimethyl acetylenedicarboxylata is interesting, since it offers a potentially general method for preparation of compounds in this series, containing the dihydroazocine ring system and the axocyclic enamine functionality possibly useful for further structural