Abstract Reaction of furo [3, 2-b] pyrroles and their benzo [b] analogues with dimethyl butynedioate and ethyl propyonate were investigated. The reaction course is influenced by substituents on the system. Products of [4+ 2] cycloaddition to the furan or pyrrole nucleus as well as products of Michael addition to the benzo [b] furo [3, 2-b] pyrrole system have been found. The structure of the products has been proven by 1 H NMR and 13 C NMR ...