PURPOSE: To provide a method for producing a sugar acetonide without using an inorganic acid, phosphorus pentoxide, iodine or a solid catalyst and without requiring the removal of water with an azeotropic mixture.
CONSTITUTION: This method is to produce a sugar acetonide from a sugar and acetone in the presence of a Lewis acid. The method comprises carrying out the reaction in the presence of a carboxylic acid derivative represented by the general formula R1-CO-X [X denotes a leaving group which can be replaced by hydroxyl group; R1 denotes methyl, ethyl, propyl, isopropyl, butyl (branched or unbranched), pentyl (branched or unbranched) or hexyl (branched or unbranched)] at a temperature within the range of 40-58°C, then cooling the resultant reaction mixture, bringing the cooled reaction mixture into contact with a dilute aqueous solution of a basic compound of an alkali metal or an alkaline earth metal, extracting the resultant solution with an aliphatic or an aromatic hydrocarbon, heating the obtained extract solution at a temperature within the range of 50-60°C, depositing and isolating a crystal of an isopropylidene sugar, then washing the crystal and removing the solvent residue.
FURANTSU DEIITORITSUHI KURINGU
HAINRITSUHI SHIYUNAIDAA
