1-Butanol → L-Ascorbic Acid

Participants

Reaction Conditions

Reaction Steps

742 g (3.75 mol) of anhydrous 2-keto-L-gulonic acid were suspended in 1.5 l (17 mol) of n-butanol and, after addition of 8 g of concentrated sulfuric acid, the mixture was evacuated to 200 mbar. After heating to 85° C., 1.1 l of water-containing n-butanol were distilled off after 2 hours. The viscous, golden-yellow-colored melt was mixed with 906 ml (8.9 mol) of perchloroethylene and rearranged at 72 to 75° C. for 17 hours after addition of 84 ml of conc. hydrochloric acid. The precipitated L-ascorbic acid was filtered off with suction, washed with n-butanol and dried in vacuo. 588 g (88%) of a pale gray crude product having a purity of 98.5% were obtained. The crude product dissolved in water. After clarifying filtration, a colorless solution was obtained from which it was possible to isolate L-ascorbic acid in a manner known from the literature. The residue (0.9%) consisted mainly of carbon.

Provenance & Evidence