TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The alkaline solution is selected from sodium hydroxide solution, potassium hydroxide solution or calcium hydroxide solution.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The crude mitiglinide calcium dihydrate is purified by recrystallization in alcohol solvent. The pH is adjusted to 1-2 with 6N hydrochloride. Preferred Components: The alcohol solvent is selected from methanol, ethanol, isopropanol or butanol. The aromatic hydrocarbon solvent is selected from toluene, xylene, ethyl benzene or mesitylene. The acid is selected from acetic acid, hydrochloric acid, hydrobromic acid, propanoic acid or paratoluene sulfonic acid. The regioisomer (r1) is 4-(3aS,7aR)-Octahydro-isoindol-2-yl-4-oxo-3-((S)-phenylmethyl)-butyric acid. ACTIVITY - Antidiabetic. No biological data given.    MECHANISM OF ACTION - Potassium channel antagonist.    EXAMPLE - About 100 g S-benzylsuccinic anhydride was suspended in 1000 ml toluene and heated at 45-50 degrees C to obtain a suspension (s1). A solution of 79 g cis-octahydroisoindole in 500 ml toluene was slowly added to suspension (s1) at 45-50 degrees C for 30-40 minutes to get a clear solution. After completion, the reaction mass was cooled and stirred for 2 hours at 25-30 degrees C. The obtained regioisomer was separated out by filtration; to the filtrate, slowly added sodium hydroxide solution (comprised of 19 g sodium hydroxide in 500 ml water) at 25-30 degrees C and stirred for 10-15 minutes. The obtained layers were separated and washed the toluene layer with 100 ml water. The aqueous layers were combined and charged with 1000 ml ethanol and then slowly added calcium chloride solution (comprised of 44 g calcium chloride in 1400 ml purified water) for a period of 45-60 minutes at 25-30 degrees C and stirred for 10-12 hours at same temperature. The resultant solid was filtered and washed with purified water and dried at 50-55 degrees C for 10 hours to obtain solid which was dissolved in 1700 ml ethanol at 60 degrees C, filtered through hyflo. The filtrate further heated to reflux temperature, followed by addition of 100 ml water and maintained at same temperature for 30 minutes; cooled to ambient temperature and maintained for 24 hours. The resultant solid was filtered, washed with ethanol and dried at 50-55 degrees C to obtain 85.0 g crude mitiglinide calcium dihydrate. The obtained product had 98% purity.