Laccase-mediated oxidation of phenolic derivatives

The laccase-catalyzed oxidation of para-alkyl phenols (p-cresol, 3,4-dimethylphenol, tyrosol, 2′-O-acetyl-tyrosol) in biphasic systems has been investigated. With all the substrates compounds similar to the so-called “Pummerer's ketone” could be isolated in reasonable yields. Accumulation of this kind of products is due to the fact that these compounds, in contrast to other dimers, are “dead-end” products, as they cannot be further oxidized by the enzyme.