2-keto-L-Gulonic acid → L-Ascorbic Acid
Reaction equation
[CH2:1]([OH:13])[C@H:2]([OH:12])[C@@H:3](O)[C@H:4]([OH:10])[C:5]([C:7]([OH:9])=[O:8])=[O:6]>O>[O:8]=[C:7]1[O:9][C@H:3]([C@H:2]([CH2:1][OH:13])[OH:12])[C:4]([OH:10])=[C:5]1[OH:6]Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 2-keto-L-gulonic acid (250 g, content: 89.6%, water: 8.6%) and trimethylcetylammonium chloride (0.275 g) was stirred in toluene (960 ml), and 35% conc. hydrochloric acid (30.0 g) was added. This mixture was stirred at 60° C. for 1 hour, a solution of hydrogen chloride gas (30.0 g) in t-butanol (130 g) was added, and the mixture was stirred at the same temperature for 5 hours. Then, about 1200 g of the solvent was distilled away under reduced pressure while continuously introducing toluene (850 ml). The residue was filtered to give crude crystals of L-ascorbic acid. The crude crystals were dissolved in water. Quantitative analysis of the solution by HPLC showed that the solution contained L-ascorbic acid (50.6 g, yield: 25.0%) and 2-keto-L-gulonic acid (146.8 g, residual ratio: 65.7%).
Sources & evidence
- ORD record
- ord-15defd4ddf26454784b8f323adb26ac7
- Source dataset
- uspto-grants-1997_06
- Patent number
- US05637734
Reaction notes
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