Mucic acid explained

Mucic acid, C6H10O8 or HOOC-(CHOH)4-COOH (galactaric acid or meso-galactaric acid) is an aldaric acid obtained by nitric acid oxidation of galactose or galactose-containing compounds such as lactose, dulcite, quercite, and most varieties of gum.[1]

Properties

Mucic acid forms a crystalline powder, which melts at 210–230 °C.[2] It is insoluble in alcohol, and nearly insoluble in cold water.[1] Due to the symmetry in the molecule, it is optically inactive even though it has chiral carbon atoms (i.e., it is a meso compound).

Reactions

When heated with pyridine to 140 °C, it is converted into allomucic acid.[1] [3] When digested with fuming hydrochloric acid for some time it is converted into αα′ furfural dicarboxylic acid while on heating with barium sulfide it is transformed into α-thiophene carboxylic acid.[1] The ammonium salt yields on dry distillation carbon dioxide, ammonia, pyrrol and other substances.[1] The acid when fused with caustic alkalis yields oxalic acid.[1]

With potassium bisulfate mucic acid forms 3-hydroxy-2-pyrone by dehydration and decarboxylation.

Use

Mucic acid can be used to replace tartaric acid in self-raising flour or fizzies.

It has been used as a precursor of adipic acid in the way to nylon by a rhenium-catalyzed deoxydehydration reaction.[4]

It has been used as a precursor of Taxol in Nicolaou Taxol total synthesis (1994).

See also

Notes and References

  1. Mucic Acid . 18 . 954.
  2. Web site: Mucic acid . ChemSpider . 30 March 2018.
  3. 10.1021/ja01382a029. The Preparation of Allomucic Acid and Certain of Its Derivatives. Journal of the American Chemical Society. 51. 7. 2167. 1929. Butler . C. L.. Cretcher . L. H. .
  4. 10.1002/anie.201310991. Highly Efficient Chemical Process to Convert Mucic Acid into Adipic Acid and DFT Studies of the Mechanism of the Rhenium-Catalyzed Deoxydehydration. Angewandte Chemie International Edition. 53. 16. 4200–4204. 2014. Li . X. . Wu . D. . Lu . T. . Yi . G. . Su . H. . Zhang . Y. . 24623498.