Abstract
2-(Methoxycarbonylmethyl)- (I), 2-cyanomethyl- (VIII), and 2-phenacyl-isoquinoli nium bromide (XII) react with dimethyl acetylenedicarboxylate, in the presence of tri-ethylamine, and form the corresponding 1, 10b-dihydropyrrolo[2, 1-a]isoquinoline (IV, X, and XIV) and aromatized compounds (V, XI, and XV). Treatment of IV, X, and XIV with hydrogen chloride in benzene, with subsequent neutralization with potassium carbonate, results in isomerization to stable 2, 3-trans-2, 3-dihydropyrrolo[2, 1-a]isoquinolines (VII, XX, and XXI).