ChemInform Abstract: Effect of Metal Ions in Organic Synthesis. Part 33. 2‐Hydroxy‐4‐pyrrolines as Stable Intermediates in the Synthesis of 1‐Aminopyrrole Derivatives.

Abstract Reaction of the azoalkenes (I) with the diketones or ketoesters (II) in the presence or absence of CuCl2 leads either to the pyrroles (III) or to the pyrrolines (IV); the latter are easily converted to (III).