Process for the preparation of optically active esters of lactic acid.

摘要

Process for the preparation of optically pure alkyl lactates by condensation of an enantiomer of lactic acid (A) with an alcohol (B) containing 1 to 12 carbon atoms, where: - the condensation of lactic acid (A) with an excess of alcohol (B) is carried out in at least one enclosure in the absence of catalyst at a temperature below 140 DEG C, in that the excess alcohol and the water produced by the esterification reaction but not the ester is removed by means of an entrainment with alcohol or by means of an entrainer, - in at least one separate enclosure the remaining alcohol is removed and the ester is separated off by distillation under reduced pressure, - in a last enclosure the residue obtained after distillation of the ester is treated with a water alcohol mixture and the mixture originating from the said treatment is introduced into the esterification enclosure.