| Autor: |
Amorim Mauro B. de, Silva Alcides J. M. da, Costa Paulo R. R. |
| Jazyk: |
angličtina |
| Rok vydání: |
2001 |
| Předmět: |
|
| Zdroj: |
Journal of the Brazilian Chemical Society, Vol 12, Iss 3, Pp 346-353 (2001) |
| Druh dokumentu: |
article |
| ISSN: |
0103-5053 |
| Popis: |
An improved procedure for the "one-pot" preparation of cathecols from methylenedioxy-ring cleavage reaction of safrole derivatives with aluminum chloride is described. In substrates substituted by conjugated electron-withdrawing groups (carboxyaldehyde or nitro groups) the regioselective formation of the easily isolable chloromethyl ether intermediates was observed. From these intermediates the syntheses of mono-O-methylated phenols (3-hydroxy-4-methoxybenzaldehyde, 2-bromo-4-methoxy-5-hydroxybenzaldehyde, 2-nitro-4-methoxy-5-hydroxybenzaldehyde and 2-methoxy-4-(2-oxoprop-1-yl)-5-nitrophenol) were accomplished. Based on these experimental data and semi-empirical (MNDO) molecular orbital calculations, a mechanistic rationale that explains the observed regioselectivities was also proposed. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
