Oxidation of primary alcohols to methyl esters using tert-butyl hypochlorite, pyridine and methyl alcohol

Abstract

When treated with tert-butyl hypochlorite, in the presence of pyridine and methyl alcohol, saturated aliphatic primary alcohols are oxidized to methyl esters in very high yields. Oxidation of benzylic alcohols, under the same conditions, yields a mixture of aldehydes and methyl esters. It appears that this reaction is a three-step process with an aldehyde and acyl chloride as the intermediates. Investigation of the relative rates of reaction reveals that benzyl alcohols are, as expected, oxidized faster than aliphatic alcohols, while the corresponding aldehydes show an opposite trend in reactivity. The reaction mechanism is proposed and the difference in the reactivity for aliphatic and benzylic aldehydes attributed to the stereoelectronic factors.