HEMIACETALS OF GLYOCYLIC ESTERS AND A PROCESS FOR THE ISOLATION OF GLYOXYLIC ESTERS

摘要

The invention relates to hemiacetals of glyoxylic esters and to a process for obtaining a glyoxylic ester having a C1 to C4 ester group from a mixture which essentially contains a glyoxylic ester of this type plus water and/or a C1 to C4 alcohol ROH. In this, the glyoxylic ester and the water and/or the alcohol are partly or completely in a chemically bonded form. A higher alcohol R'OH having a boiling point above 180 DEG C. is added, and distillation is carried out under a pressure not exceeding 800 mbar to remove first the water and/or the alcohol ROH and then the glyoxylic ester.