| abstract |
Ascorbic acid is prepared from a 1,4-lactone selected from gulono-1,4-lactone, galactono-1,4-lactone, idono-1,4-lactone and talono-1,4-lactone by a process comprising protection of the hydroxyl groups of the lactone so as to form an intermediate having a free hydroxyl group at either, but not both, the 2- or 3-position, oxidizing this free hydroxyl group to a keto group and hydrolyzing the oxidized intermediate to remove the hydroxyl-protecting groups. |