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Solvent influence on model oxidations of alpha-tocopherol.

M Sumarno·E Atkinson·C Suarna·J K Saunders·E R Cole·P T Southwell-Keely
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Abstract

(+/-)-alpha-Tocopherol has been oxidised with t-butyl hydroperoxide in chloroform in order to simulate in vivo oxidations due to lipid hydroperoxides. t-Butyl hydroperoxide proved to be a weak oxidant and failed to oxidise alpha-tocopherol in 3 h at 60 degrees C. Inclusion of a small amount of ethanol in the reaction mixture brought about immediate oxidation and the formation of a new product, 5-ethoxymethyl-7,8-dimethyltocol in addition to the spiro dimer and spiro trimer of alpha-tocopherol, alpha-tocopherylquinone and 5-formyl-7,8-dimethyltocol. Formation of 5-ethoxymethyl-7,8-dimethyltocol increased with increasing concentrations of ethanol, up to a maximum of 59% at 20% ethanol. Further increase in ethanol concentration brought about a decrease in the oxidation of alpha-tocopherol and in the formation of 5-ethoxymethyl-7,8-dimethyltocol. Oxidation of the tocopherol model compound 2,2,5,7,8-pentamethyl-6-hydroxychroman under similar conditions produced the analogous product, 5-ethoxymethyl-2,2,7,8-tetramethyl-6-hydroxychroman together with 5-formyl-2,2,7,8-tetramethyl-6-hydroxychroman and 2-(3'-hydroxy-3'-methylbutyl)-3,5,6-trimethylbenzo-1,4-quinone.

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CatalysisChloroformEthanolIsomerismLipid PeroxidesOxidation-ReductionPeroxidesQuinonesSolventsVitamin Etert-ButylhydroperoxideJournal Article

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M Sumarno, E Atkinson, C Suarna, J K Saunders, E R Cole, P T Southwell-Keely. 1987-08-15. Solvent influence on model oxidations of alpha-tocopherol.. https://doi.org/10.1016/0005-2760(87)90101-9

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