Nuclear oxidation in flavones and related compounds. Part XXXVI. Oxidation of some hydroxy isoflavones

Using methods of nuclear oxidation 7 : 8-dihydroxy-2-methyl isoflavone, 5 : 7 : 8-trihydroxyisoflavone and 5 : 7 : 8-trihydroxy-2-methyl isoflavone and their derivatives have been prepared. Demethylation of the 5 : 7 : 8-trimethoxy isoflavones with or without a 2-methyl group does not produce isomeric change in the trihydroxy product. It could therefore be concluded that a phenyl group in the 3-position prevents this isomeric change just like a methoxyl (hydroxyl) in the same position and that substitution in the 2-position has no influence