Oxidation of mandelic acid derivatives catalysed by Bi(0)/O2 systems:: mechanistic considerations

Mandelic acid and some aryl substituted derivatives were oxidised under molecular oxygen and a catalytic amount of Bi(0). The corresponding aldehydes and/or the carboxylic acids were obtained selectively depending on the nature of the substituent. Aldehydes and alpha-keto acids were oxidised under the same Bi(0)/O-2 system and a-keto acids were proposed as intermediates in the formation of benzoic acid derivatives. (C) 2003 Elsevier Science Ltd. All rights reserved.