The potassiumt-butoxide-catalysedoxygenation of an α-tocopherolmodel compound, 2,2,5,7,8-penta-methylchroman-6-ol, gave 5-hydroxy-2,2,5,7,8-penta-methylchroman-6(5H)-one (2) and 7,8-dihydro-5,7-dihydroxy-8-methylene-2,2,5,7-tetramethychroman-6(5H)-one, and 6-hydroxy-2,2,6,7,8-pentamethylchroman-5(6H)- one which was found to be formed as the result of the acyloin rearrangement of (2).
Oxygenations of vitamin E (.alpha.-tocopherol) and its model compound, 2,2,5,7,8-pentamethylchroman-6-ol, in the presence of potassium superoxide suspended in tetrahydrofuran, and unusual acyloin rearrangements