Pyridinium salts Py⁺-CH₂-EWG (EWG = CO₂Et, CONEt₂, CN, COMe, COPh) reacted with Michael acceptors Ar-CH=C(CO₂Et)(Acc) (Acc = CO₂Et, COMe, SO₂Me, CONH₂) at ambient temperature in the presence of base to give [3 + 2]-cycloadducts by stepwise [3 + 2]-cycloaddition of the intermediate pyridinium ylides. Treatment of the crude reaction mixtures with 1 equiv. of chloranil and atmospheric oxygen in the presence of sodium hydroxide gave 1-(ethoxycarbonyl)indolizines by dehydrogenation and elimination of the acceptor group (Acc). A good yield of indolizine was also obtained from Py⁺-CH₂CN and iPr-CH=C(CO₂Et)₂, which indicates that this method is not restricted to aromatic Michael acceptors. Structurally related isoquinolinium salts react with Michael acceptors analogously to give pyrrolo[2,1-a]isoquinolines.