Repositório Digital

A- A A+

Molecular sieves mediated green per-O-acetylation of carbohydrate templates and lipase catalyzed regioselective alcoholysis of 2,3,5-tri-O-acetyl-D-ribonolactone

.

Molecular sieves mediated green per-O-acetylation of carbohydrate templates and lipase catalyzed regioselective alcoholysis of 2,3,5-tri-O-acetyl-D-ribonolactone

Mostrar registro completo

Estatísticas

Título Molecular sieves mediated green per-O-acetylation of carbohydrate templates and lipase catalyzed regioselective alcoholysis of 2,3,5-tri-O-acetyl-D-ribonolactone
Autor Cardozo, Herbert Martins
Ribeiro, Thaís de Freitas
Sá, Marcus Mandolesi
Sebrão, Damianni
Nascimento, Maria da Graça
Silveira, Gustavo Pozza
Abstract The per-O-acetylation of D-ribono-1,4-lactone and representative carbohydrates through the combination of acetic anhydride and molecular sieves under solvent-free conditions is demonstrated. The use of 13X/KCl molecular sieves as the heterogeneous catalyst was found to be more efficient than the excess of pyridine normally employed in the conventional method, giving high yields of the expected peracetylated product after 3 h at 25°C or 1 h at 50°C. The transformation can be carried out in gram scale and in an open flask. Additionally, the catalyst is readily separated from the reaction medium and can be reutilized without significant loss of activity. This green procedure for acetylation was extended to D-ribonolactone derivatives and natural carbohydrates. To demonstrate the synthetic utility of the method, 2,3,5-tri-O-acetyl-D-ribonolactone was selected as the substrate for the regioselective alcoholysis of acetyl group catalyzed by Candida antarctica lipase B in EtOH to selectively produce 2,3-di-O-acetyl-D-ribonolactone in gram scale.
Contido em Journal of the Brazilian Chemical Society. São Paulo. Vol. 26, no. 4, p. 755-764
Assunto Carboidratos
Lipase
Peneira molecular
Zeolitas
[en] CAL-B
[en] D-ribonolactone
[en] Molecular sieves
[en] Per-O-acetylation
[en] Regioselective alcoholysis
Origem Nacional
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/131293
Arquivos Descrição Formato
000981688.pdf (209.9Kb) Texto completo (inglês) Adobe PDF Visualizar/abrir

Este item está licenciado na Creative Commons License

Este item aparece na(s) seguinte(s) coleção(ões)


Mostrar registro completo

Percorrer



  • O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia.
    Projeto gráfico elaborado pelo Caixola - Clube de Criação Fabico/UFRGS Powered by DSpace software, Version 1.8.1.