Patent ID: 6288272
Filing Date: 2001-09-11
Classification: C07B,C07D,C12P

Abstract:
A continuous process for producing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by the following Formula 1 from polysaccharide source, which comprises the following steps:(a) Enzymatic reaction of amylopectin to .alpha.-(1,4) linked oligosaccharide expressed by the Formula 2;(b) Oxidation of the oligosaccharide by running basic anion exchange resin with an oxidant to afford (S)-3,4-dihydroxybutyric acid expressed by the Formula 3; and(c) Subsequent esterification with alcohol in the presence of an acid catalyst to afford ester of (S)-3,4-dihydroxybutyric acid expressed by the Formula 1. ##STR6##wherein, M represents hydrogen, alkali metal or alkali earth metal atom; R represents linear or branched alkyl group with 1.about.5 carbon atoms.