SYNTHESE DE PYRROLES ET D'OXAZOLES PAR PYROLYSE DE N-(HYDROXY-2' ETHYL) AMINO-3 PROPENOATE

Article abstract of DOI:10.1016/S0040-4020(01)81018-8

The gas phas pyrolysis of various N-(2'-hydroxyethyl)-3-amino propenoates 1-6 and N-(2'-hydroxy-2'-phenyl ethyl)-3-amino propanoate 7-9 at 390 deg C-420 deg C leads respectively to formylpyrroles 11-16 and benzoylpyrroles 17-19 and, in some cases, to substituted oxazoles 36-39.The results are best explained by the intermediate formation of a dicarbonyl derivative followed either by an intramolecular thermal crotonisation or a six ? electrocyclization of an azomethine ylide.