Abstract: A method of performing an oxidation reaction in which an alkali hypohalite is used as an oxidizing agent which comprises: carrying out the oxidation reaction in an aqueous medium with concurrently distilling off a solvent used in the reaction as the reaction proceeds under a reduced pressure.The method is in particular useful for the oxidation of diacetone-L-sorbose to diacetone-2-keto-L-gulonic acid in water. The reaction temperature is so accurately controlled that the same optimum yield of diacetone-2-keto-L-gulonic acid is obtained by the use of a reduced amount of sodium hypochlorite as compared with the conventional manner of reaction under atmospheric pressure.

Abstract: A method of regenerating hydrous zeolite which contains acetone as well as water after having been used to dehydrate hydrous acetone of the invention which comprises: placing the hydrous zeolite in a closed system in which a heated inert gas is circulated at a pressure more than atmospheric pressures to bring the inert gas into contact with the hydrous zeolite to remove the acetone and water from the zeolite, and condensing the acetone and water in the closed system and removes them from the closed system.The method is in particular useful for regenerating hydrous zeolite which has been used to dehydrate hydrous acetone resulting from the reaction of L-sorbose with acetone to produce diacetone-L-sorbose, and which thus contains acetone as well as about 1000-4000 ppm of water therein.