PURPOSE: To obtain new optically active diacetylester and racemic hydrated diacetylester of α-glycero-phosphoryl-choline used for the treatment of dislipidemia and hyperlipoproteinemia and useful to treat cerebral involutions of the aged.

CONSTITUTION: One of optically active diacetylester and racemic hydrated diacetylester of α-glycero-phosphoryl-choline is 1,2-di-O-acetyl-glycero-3- phosphoryl-choline-hydrate of formula I (where*shows asymmetric carbon). The compd. of the formula I is obtd. by condensing 2-chloro-2-oxa-1,3,2- dioxaphosphorane of formula II with L-1,2-di-O-acetyl-glycerol of formula III in a nonpolar solvent, allowing the resultant intermediate of formula IV to react with excess trimethylamine under pressure, dissolving the resultant anhydrous L-1,2-di-O-acetyl-glycero-phosphoryl-choline in an alcohol and carrying out elution with a cation exchange resin, concn. and crystallization.