Chemistry of 2-Methoxy-2,5-cyclohexadienones. II.1) Oxidation of 2-Methoxy-4,4-dimethyl-2,5-cyclohexadienone2)

Abstract

2-Methoxy-4,4-dimethyl-2-cyclohexenone (II) afforded 5,6-epoxy-6-methoxy-4,4-dimethyl-6-hexanolide (III) upon reaction with m-chloroperbenzoic acid in 1,1,1-trichloroethane. On the other hand, the treatment of II with the same reagent in an aqueous disodium orthophosphate-methylene chloride system at 4°C gave 2,3-epoxy-2-methoxy-4,4-dimethylcyclohexanone (V), which could be converted to methyl 2-hydroxy-l-methoxy-3,3-dimethylcyclopentanecarboxylate (VI). 2-Methoxy-4,4-dimethyl-2,5-cyclohexadienone (I) afforded 5,6-epoxy-2-methoxy-4,4-dimethyl-2-cyclohexenone (VIII) upon reaction with hydrogen peroxide in a basic medium. The reaction of I with m-chloroperbenzoic acid at room temperature gave 5,6-epoxy-6-methoxy-4,4-dimethyl-2-cyclohexenone (X). Neither VIII nor X gave the expected 2,3,5,6-diepoxy-2-methoxy-4,4-dimethylcyclohexanone (VII), but afforded 2,3,5,6-diepoxy-6-methoxy-4,4-dimethyl-6-hpYanr»1irJp (IX). © 1984, The Pharmaceutical Society of Japan. All rights reserved.