Guaiacylglycerol-&guaiacyt ether (I) was treated with alkaline hydrogen peroxide under simulated technical bleaching conditions in the presence and absence of a peroxide stabilization reagent, Na5DTPA (sodium diethylenetriaminepentaacetate) and with molecular oxygen under similar conditions. The reaction products were characterized and their yields determined using a combination of gas chromatography and gas chromatography mass spectrometry.
In the reaction of I with peroxide, the principal reaction consisted of the displacement of the side chain (Dakin-like reaction) initiated by molecular oxygen and/or other peroxide decomposition products. The displaced side chain, a-0-(2-methoxyphenyl)glyceraldehyde, subsequently was dehydrated to a-guaiacoxyacrolein which was oxidized by peroxide to guaiacol and glycolic acid. c~-Guaiacoxyacrolein also gave evidence of undergoing competing condensation reactions in the alkaline medium. The influence of NasDTPA in controlling peroxide decomposition was evident after comparing the yields and types of products formed when I was reacted with peroxide in the presence and absence of this stabilizer.
The findings are discussed in terms of their relationship to technical peroxide bleaching.