SYNTHESIS OF COUMARINS AND DERIVATIVES .1. BIOMIMETIC SYNTHESIS OF ESCULETIN AND HALOGENATED DERIVATIVES

• Tipo: Artigo em Revista Científica Internacional
• Data: 1992

Autores

BORGES, F (Autor) FFUP; PINTO, M (Autor) FFUP

Revista

Título: Helvetica Chimica Acta

Vol. 75

ISSN: 0018-019X

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 9 Citações

Scopus - 12 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-001-Q1S

Abstract (EN): Esculetin (1) and the novel compounds 5-chloroesculetin (5) and 5-bromoesculetin (6) were obtained from a light-induced cyclization of trans-caffeic acid (3) catalyzed by [FeNa(edta)] and/or H2SO4, HCl, or HBr (Scheme 1). The experimental conditions for trans-cis-isomerization of the cinnamic-acid derivative 3 and subsequent nonenzymatic cyclization were described. The photoperiod and the presence of air and iron-chelate catalyst are shown to be important parameters that markedly affect yields. The reactions probably occur by a free-radical mechanism involving a photo-initiated one-electron redox process (Scheme 2).

Idioma: Inglês

Tipo (Avaliação Docente): Científica