Process for increasing the production or recovery yields of hemiacetal-esters of glyoxylic acid

摘要

The process comprises the hot treatment at a temperature of 80 DEG to 160 DEG C. by an amount of 5 to 50% of 85% of phosphoric acid, of the residues resulting from the distillation of reaction media containing hemiacetal-esters under substantially anhydrous conditions. These reaction media are selected from among those resulting from the reaction of alcohols and glyoxylic acid and those resulting from the treatment of glyoxylic hemiacetal-esters with P2O5.