Levulinic acid synthesis via regiospecific carbonylation of methyl vinyl ketone or of its reaction products with hydrochloric acid or an alkanol or of a mixture of acetone with a formaldehyde precursor catalyzed by a highly active Pd-HCI system

Article abstract of DOI:10.1016/0304-5102(90)85045-J

Levulinic acid and its esters are synthesized by the palladium-catalyzed carbonylation of (i) 3-buten-2-one, (ii) 4-alkoxy-2-butanone, (iii) 4-chlorobutanone, and (iv) the products of reaction of acetone with formaldehyde or a formaldehyde precursor, preferably trioxane, in the presence of water or an alkanol containing dissolved hydrochloric acid. The synthesis is regio-specific. The catalytic system is highly active only in the presence of excess hydrochloric acid at 100-110°C. The presence of the acid is essential for catalytic activity. The yield increases with increasing carbon monoxide pressure, concentration of palladium, concentration of the acid (up to a HCl/substrate ratio of 2.5-3), concentration of the substrate and of the alkanol dissolved in a solvent such as benzene.