Reichstein process

Reaction steps

• hydrogenation of D-glucose to D-sorbitol, an organic reaction with nickel as a catalyst under high temperature and high pressure.
• Microbial oxidation or fermentation of sorbitol to L-sorbose with acetobacter at pH 4-6 and 30 °C.
• protection of the 4 hydroxyl groups in sorbose by formation of the acetal with acetone and an acid to Diacetone-L-sorbose
• Organic oxidation with potassium permanganate followed by heating with water gives the 2-Keto-L-gulonic acid
• The final step is a ring-closing step or gamma lactonization with removal of water.
• Intermediate 5 can also be prepared directly from 3 with oxygen and platinum

Importance

Literature

• Boudrant, J. : Microbial processes for ascorbic acid biosynthesis: a review. In: Enzyme Microb Technol. 12; 322–9; ;
• Bremus, C. et al. : The use of microorganisms in L-ascorbic acid production. In: J Biotechnol.'' 124; 196–205; ;