Dehydroascorbic acid is shown to be converted to 2-(threo-l,2,3-trihydroxypropyl)tartronic acid in aqueous alkaline solutions. The structure of the acid was determined by mass spectrometry of its acyclic Me3Si derivative. Mass spectrometric and chromatographic data are compared with those of related compounds. The acid is formed by a benzilic acid rearrangement of the intermediate 2,3-hexodiulo...

hypophosphite for the conversion of D-glucuronolactone into L-ascorbic acid. 9. The presence of borate or Antabuse, each at mm-concentration, inhibits the conversion of Dglucuronolactone into L-ascorbic acid to about 50 %. 10. The optimum conditions for the action of the enzyme system have been studied. 11. The biosynthesized ascorbic acid has been identified by paper chromatography and by a bi...