Microbiological Oxidation of Isophorone to 4-Hydroxyisophorone and Chemical Transformation of 4-Hydroxyisophorone to 2,3,5-Trimethyl-p-benzoquinone

Oxidation of isophorone by various fungi was examined. Aspergillus niger oxidized isophorone to 4-hydroxyisophorone, 3-hydroxymethyl-5,5-dimethyl-2-cyclohexen-1-one and 5-hydroxymethyl-3,5-dimethyl-2-cyclohexen-1-one. 4-Oxoisophorone obtained by chromic acid oxidation of 4-hydroxyisophorone was transformed to 2,3,5-trimethyl-p-benzoquinone by acid treatment.