Oxoammonium salts.: 9.: Oxidative dimerization of polyfunctional primary alcohols to esters.: An interesting β oxygen effect

The use of the oxidant 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate in combination with pyridine for the oxidative, dimeric esterification of primary alcohols is described. The ester is the predominant product of the reaction with alcohols containing a beta oxygen. In the absence of a beta oxygen, the corresponding aldehyde is found in appreciable amounts, but a concentration effect can be observed. In the absence of pyridine, little ester is formed, and no appreciable reaction takes place with beta-oxygenated compounds. delta Lactones have been prepared from diethylene glycol and 2,2'-thiodiethanol, without sulfur oxidation.