Formation de Chromones (O,S,Se) et D'Autres Dérivés par Action du Dicétène sur le Phénol, le Thiophénol et le Sélénophenol. Contribution â L'étude des Réactions de Pechmann et Simonis

✍ Scribed by A. Ruwet; D. Janne; M. Renson

• Publisher: Wiley (John Wiley & Sons)
• Year: 2010
• Weight: 347 KB
• Volume: 79
• Category: Article
• ISSN: 0037-9646
• DOI: 10.1002/bscb.19700790110

✦ Synopsis

CONTRIBUTION A L'ETUDE DES REACTIONS DE PECHMANN ET SIMONIS

A. RUWET, D. JANNE et M. RENSON

The Pechmann and Simonis reactions are investigated with phenols (0, S, Se). Thio and selenophenols give thio-1 and seleno-1 chromones (Simonis reaction). Several cyclizing agents are studied. Ethyl acetylacetate is replaced by diketene. They give the Simonis reaction. From diketene we synthesize phenyl acetylthiol and selenolacetates which possess thiol or selenolester function. The cyclization produces rearrangement and leads to Simonis reaction. These 2 new ways give also chromones from oxygen compounds. We don't isolate thio-l and seleno-l coumarins. However, we obtain dimethyl-2,6 phenylselenolcarboxylate-3 y-pyrone which is yet converted to seleno-1 chromone. We discuss all these results: the Pechmann and Simonis reactions intermediates are to be reconsidered, especially phenyl acetylacetates (0, S, Se).