Gif chemistry: new evidence for a non-radical process

When performed under a nitrogen monoxide atmosphere, Gif oxidation of cyclo hexane with hydrogen peroxide gives no changes in activity or selectivity, showing that tripler oxygen is neither formed nor required in the oxidation . Gif oxidation of cis- and trans-decalin occurs preferentially at secondar y positions giving high yields of ketones. Oxidation of tertiary positions is as low as approximately 5% and probably involves free radicals. Oxidatio n of cyclohexane in the presence of mannitol gives no significant loss of a ctivity, showing that OH radicals are not involved in Gif oxidation. Based on these results the mechanism of Gif oxidation is discussed. (C) 2001 Else vier Science Ltd. All rights reserved.