SYNTHESIS OF FUNCTIONALIZED 1-METHYLCHROMENO[3,4-b]PYRROL-4(3H)-ONES via THE BARTON–ZARD REACTION STARTING FROM PSEUDONITROSITES

Abstract

A method for the preparation of chromeno[3,4-b]pyrrol-4(3H)-ones via the synthesis of the corresponding 3-arylpyrrole-2-carboxylates from pseudonitrosites by the Barton–Zard reaction was developed. As a result of selective O-demethylation upon exposure to BBr3, the lactone ring closes with the formation of substituted chromeno[3,4-b]pyrrolones in moderate yields.