| Popis: |
The previously proposed mechanism for lignin oxidation to vanillin was supported experimentally. This process begins with the formation of a phenoxyl radical and ends with the step of retroaldol cleavage of substituted coniferaldehyde to vanillin. The oxidation of model compounds was studied, and experimental evidence for the proposed mechanism was obtained. The postulated intermediate coniferyl alcohol was detected in the oxidation of eugenol. The proposed mechanism was supported by kinetic data and the composition of the oxidation products of vanillideneacetone, lignosulfonates, eugenol, isoeugenol, guaiacylethanol, and guaiacylpropanol. |
