Sodium borohydride-iodine mediated reduction of γ-lactam carboxylic acids followed by DDQ mediated oxidative aromatisation:: a simple approach towards N-aryl-formylpyrroles and 1,3-diaryl-formylpyrroles

A simple methodology for the conversion of substituted N-aryl-gamma-lactam 2/3-carboxylic acids to substituted N-aryl-2/3-formyl-pyrroles has been developed. Several N-aryl-gamma-lactam 2/3-carboxylic acids were reduced to substituted (N-aryl-pyrroliden-2/3-yl)-methanols in good yields by using the NaBH4-I-2 system. Aromatisation and in situ oxidation of these alcohols using DDQ produced N-aryl-2/3-formyl-pyrroles, which act as key starting material and intermediates in the synthesis of several bioactive compounds. (c) 2007 Elsevier Ltd. All rights reserved.