Glyoxylic acid Glyoxylic acid Glyoxylic acid or oxoacetic acid is an organic compound. Together with acetic acid, glycolic acid, and oxalic acid, glyoxylic acid is one of the C carboxylic acids. It is a colourless solid that occurs naturally and is useful industrially. Glyoxylic acid is usually described with the chemical formula OCHCOH, i.e. containing an aldehyde functional group (see image in upper right). The aldehyde in fact is not observed in solution or as a solid. As seen for many other aldehydes, it exists most commonly as the hydrate. Thus, the formula for glyoxylic acid is really (HO)CHCOH, described as the
Organic compound they are classed as "metalorganic". Likewise, it is also unclear whether metalorganic compounds should automatically be considered organic. The relatively narrow definition of organic compounds as those containing C-H bonds excludes compounds that are (historically and practically) considered organic. Neither urea nor oxalic acid is organic by this definition, yet they were two key compounds in the vitalism debate. The IUPAC Blue Book on organic nomenclature specifically mentions urea and oxalic acid. Other compounds lacking C-H bonds but traditionally considered organic include benzenehexol, mesoxalic acid, and carbon tetrachloride. Mellitic acid, which contains no C-H bonds, is considered a possible organic