PRODUCTION OF D-(-)-PANTOLACTONE

PURPOSE:To obtain the titled compound having optical purity, easily in high yield with simple operation using an inexpensive reagent, on an industrial scale, by reacting DL-pantolactone with an alkali and subjecting the resultant compound to optical resolution with a specific optical resolution agent. CONSTITUTION:DL-pantolactone is made to react with an alkali such as NaOH in a solvent (preferably ethanol, etc.). The obtained alkali metal or alkaline earth metal salt of DL-pantoic acid is subjected to lactonization and optical resolution in a solvent (preferably ethanol, etc.) in the presence of optically active D-10-camphor-sulfonic acid as the optical resolution agent at -100-+25 deg.C, the solvent is distilled out under reduced pressure and the residue is extracted with a solvent such as methylene chloride and dried. The dried product is extracted with a solvent, which is distilled off under reduced pressure to obtain the objective compound. USE:A synthetic intermediate for D-(+)-pantothenic acid Ca salt, etc. useful as medicinal drugs, feed additive for chicken raising or hog raising, or a vitamin complex, etc.