COMPARATIVE-STUDY OF OZONATION OF 2 LIGNIN MODEL COMPOUNDS - CONIFERYL ALCOHOL AND FERULIC ACID - IDENTIFICATION OF SOME BY-PRODUCTS

The objective of our study was to compare the reactivity of coniferyl alcohol and ferulic acid with ozone at acidic pH in terms of ozone dem and and byproducts formation. Both structures exert an ozone demand of about two moles of ozone per mole of initial compound. Similar ozonat ion byproducts were identified using gas chromatography/mass spectrome try analysis. Using a low ozone dose (below the ozone demand), byprodu cts were principally aromatic structures, with vanillin, 3,4-dihydroxy -5-methoxybenzaldehyde and vanillic acid as the main compounds. Applyi ng a higher ozone dose (above the ozone demand), furan structures were produced. A reaction mechanism is suggested to explain the formation of such structures. A quantitative study showed that coniferyl alcohol was a stronger precursor of vanillin and vanillic acid than ferulic a cid.