On the role of retroaldol reaction in the process of lignin oxidation into vanillin. Kinetics of the vanillideneacetone cleavage in alkaline media

Kinetics and selectivity of the retroaldol reaction of vanillideneacetone in the alkaline media were studied. The reaction is of first order with respect to substrate and alkali concentration. The pH dependencies of the rates of vanillin formation in the processes of lignosulfonates and vanillideneacetone oxidation agree almost quantitatively. This indicates that the retroaldol reaction plays an important role in the alkaline oxidative destruction of lignins.