5-Arylpyrrolidine-2-carboxylic Acid Derivatives as Precursors in the Synthesis of Sulphonyl-substituted Pyrroles

cis-5-Arylpyrrolidine-2-carboxylates, obtained by 1,3-dipolar cycloaddition reactions from glycine aryl aldimines and vinyl sulfones, undergo oxidative aromatization under the action of Mn(IV) oxide to form the corresponding 5-arylpyrrole-2-carboxylates in high yields. Factors responsible for the retention of the sulfonyl substituent in the pyrrole backbone were determined.