Abstract: Regioselective synthesis of α-cyanopyrroles (vs. α-alkoxycarbonylpyrroles) using oximinocyanoacetate esters in a Knorr-type reductive condensation with β-diketones can be directed by the presence of water. Thus, methyl oximinocyanoacetate was reacted with pentane-2, 4-dione in hot acetic acid in the presence of zinc dust to give exclusively 3, 5- dimethylpyrrole-2-carbonitrile when the acetic acid was wet; whereas, in glacial acetic ...
