Publicação
Synthesis of new hydroxy-2-styrylchromones
| Resumo: | Hydroxy-2-styrylchromones 5a−i were prepared by debenzylation of benzyloxy-2-styrylchromones 3a−i, which were synthesised by the Baker−Venkataraman method. The last step of this method, the cyclodehydration 5-aryl-3-hydroxy- 1-(2-hydroxyaryl)-2,4-pentadien-1-ones 2a−i, was carried out with a catalytic amount of iodine, or p-toluenesulfonic acid, in DMSO. Benzyloxy-3-cinnamoyl-2-styrylchromones 4a−f were obtained as by-products in both procedures, but the latter procedure gave benzyloxy-2- styrylchromones 3a−i in better yields. The structures of all new compounds were established by extensive NMR studies. |
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| Autores principais: | Santos, Clementina M.M. |
| Outros Autores: | Silva, Artur; Cavaleiro, José |
| Assunto: | Rearrangements Cyclizations Protecting groups Heterocycles |
| Ano: | 2003 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Hydroxy-2-styrylchromones 5a−i were prepared by debenzylation of benzyloxy-2-styrylchromones 3a−i, which were synthesised by the Baker−Venkataraman method. The last step of this method, the cyclodehydration 5-aryl-3-hydroxy- 1-(2-hydroxyaryl)-2,4-pentadien-1-ones 2a−i, was carried out with a catalytic amount of iodine, or p-toluenesulfonic acid, in DMSO. Benzyloxy-3-cinnamoyl-2-styrylchromones 4a−f were obtained as by-products in both procedures, but the latter procedure gave benzyloxy-2- styrylchromones 3a−i in better yields. The structures of all new compounds were established by extensive NMR studies. |
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