How to synthesise high purity, crystalline D-glucaric acid selectively

Glucaric acid has potential applications in food, pharmaceutical and polymer industries yet no methodology exists within the public domain for isolation of this key bio-derived platform molecule as a pure, crystalline solid. Here we demonstrate the difficulties, which arise in doing so and report development of a process for derivation of free-glucaric acid from its Ca2+/K+ glucarate salts, which are both commercially available. Employing Amberlyst-15 (H+) exchange resin and azeotrope drying, powdered glucaric acid is prepared at > 99.96 % purity in 98.7 % dry yield

Oxidation of d-Glucose to Glucaric Acid Using Au/C Catalysts

The reactivity of Au and AuBi nanoparticles supported on activated carbon AC was investigated in the direct oxidation of glucose to glucaric acid. The catalysts were very active, regardless of the Au nanoparticles size, but the catalyst with the smallest average particle diameter was the least selective to glucaric acid because of the enhanced consecutive oxidative degradation of the intermediately formed gluconic acid. The reaction network included the fast oxidation of glucose to gluconic acid, which was the only primary product, and its consecutive oxidation into either glucaric acid or lighter mono and dicarboxylic acids. The best glucaric acid yield obtained with a AuBi/AC catalyst (Au/Bi 3:1) was 31 %, with 18 % residual gluconic acid. The control of reaction parameters was essential to achieving the best selectivity. Specifically, the glucose concentration turned out to be a critical parameter in relation to O2 pressure and to glucose/metal ratio