PROCESS FOR THE PREPARATION OF LACTIC-ACID ESTERS

摘要

1. A process for the preparation of an optically pure alkyl D- or L-lactate by reaction of calcium lactate, prepared by fermentation, with an alcohol in the presence of a strong acid, wherein the crude fermentation mixture is filtered while hot, the calcium lactate is isolated as a solid from the filtrate by spray drying and is reacted with an alcohol in the presence of an acid which forms a readily water-soluble calcium salt, the water present in the reaction mixture or formed during the esterification is separated off by azeotropic distillation with the aid of an entraining agent, and the lactic acid ester is isolated from the reation mixture in a conventional manner.