Synthesis and structural aspects of some intermediates in furofuran lignan synt...

• Autor(es): Esteves, Ana Paula ; Lemos, Maria A. ; Medeiros, Maria José ; Rodrigues, Lígia M.
• Data: 2004
• Identificador Persistente: http://hdl.handle.net/1822/1960
• Origem: RepositóriUM - Universidade do Minho
• Assunto(s): Radical cyclisation; Hypophosphite salt; Furofuran lignans
• Tipo de Documento: Artigo
• Idioma: Inglês

Descrição

The synthesis of some intermediates of furofuran lignans was accomplished by a chemical cyclisation reaction using N-ethylpiperidine hypophosphite and azobisisobutyronitrile. This reaction afforded the 5-exo-dig cyclic compound as the major product along with another isomeric cyclic compound which possess an endocyclic double bond. A brief discussion is presented to explain the formation of these isomeric cyclic compounds by a base-catalysed tautomerism mechanism. Some structural aspects are discussed based on nuclear magnetic resonance data.