Synthese de pyrroles et d'oxazoles par pyrolyse de N-(hydroxy-2′ ethyl) amino-3 propenoate
作者:Catherine Pale-Grosdemange、Josselin Chuche
DOI:10.1016/s0040-4020(01)81018-8
日期:1989.1
pyrolysis of various N-(2′-hydroxyethyl)-3-amino propenoates 1–6 and N-(2′-hydroxy-2′-phenyl ethyl)-3-amino propenoate 7–9 at 390°–420°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 dicarbonyl derivative followed either by an intramolecular thermal crotonisation
The reactions of Boc-β-amido- and β-amino acrylates, in which the CC possesses both nucleophilic and electrophilic sites, were investigated under acidic conditions. The trifluoroacetic-acid induced cyclization of the β-amido acrylates to the corresponding oxazolidin-2-ones involves a rarely seen nucleophilic attack of the carbamate carbonyl group. The cyclotrimerization of β-amino acrylates to N-substituted