Pyridinium Chlorochromate Releases Quinones from Hydroquinone Silyl Ethers.

Article abstract of DOI:10.1021/jo00329a013

The pyridinium chlorochromate oxidation of six bis(trimethylsilyl) and six bis(tert-butyldimethylsilyl) ethers of p-hydroquinones at room temperature in methylene chloride solution gave the corresponding quinones in 60-90percent yield.The bis(trimethylsilyl) ethers were slightly more reactive than the bis(tert-butyldimethylsilyl) ethers.High oxidation efficiency was indicated by a 1:1 molar stoichiometry; however, more convenient reaction times were obtained at a 2:1 molar ratio of pyridinium chlorochromate (PCC) to hydroquinone silyl ether.The mechanism is discussed based upon comparisons of relative reaction rates with electrochemical oxidation potentials.