Synthesis 2008(19): 3131-3141  
DOI: 10.1055/s-2008-1067273
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Preparation of the Maleic Anhydride Nucleus from Dichloro γ-Lactams: Focus on the Role of the N-Substituent in the Functional Rearrangement and in the Hydrolytic Steps

Franco Ghelfi*a, Mariella Pattarozzia, Fabrizio Roncagliaa, Andrew F. Parsonsb, Fulvia Fellugac, Ugo M. Pagnonia, Ennio Valentinc, Adele Muccia, Franco Bellesiaa
a Dipartimento di Chimica, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
Fax: +39(59)373543; e-Mail: ghelfi.franco@unimore.it;
b Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
c Dipartimento di Scienze Chimiche, Università di Trieste, via Licio Giorgieri 1, 34127 Trieste, Italy
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Publikationsverlauf

Received 26 May 2008
Publikationsdatum:
05. September 2008 (online)

Abstract

The preparation of the 3,4-dialkyl-substituted maleic anhydride nucleus, through the functional rearrangement of dichloro γ-lactams, allowed the comparison of various N-substituents in the functional rearrangement step. The 2-pyridyl group proved to be the most appropriate N-substituent for the hydrolysis of the 5-methoxy-1,5-dihydro-2H-pyrrol-2-one intermediate into the 5-hydroxy adduct, and for the hydrolysis of the maleimide nucleus into the maleic anhydride. The oxidation of the 5-hydroxy-1,5-dihydro-2H-pyrrol-2-one into the corresponding maleimide was achieved with manganese(IV) oxide.