Oxidative Decarboxylation of Propiolic Acids

Article abstract of DOI:10.1021/jo00177a025

The combination of iodine and iodine pentoxide in methanol was used to convert phenylpropiolic acid and 2-hexynoic acid to the corresponding ketal esters of one less carbon.In both cases, iodoacetylenic compounds were shown to be intermediates.In the case of the phenylpropiolic acid, a diiodoalkene was isolated and shown to be a second intermediate.