Oxidation of substituted phenols with chlorine dioxide

Chlorine dioxide was used to oxidize sterically hindered phenols and their derivatives (2,6-di- tert butylphenol, 2,6-diisobornylphenol, 2,6-di- tert -butyl-4-methylphenol, 2,6-diisobornyl-4-methylphenol, and 3,5-diisobornyl-4-hydroxybenzaldehyde) in organic solvent.