Patent ID: 6251642
Filing Date: 2001-06-26
Classification: C07B,C07D,C12P

Abstract:
A continuous process for producing optically pure (S)-3-hydroxy-.gamma.-butyrolactone 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 contacting with a basic anion exchange resin and with an oxidant to afford (S)-3,4-dihydroxybutyric acid expressed by the Formula 3;(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 4; and(d) cyclization of the prepared ester of (S)-3,4-dihydroxybutyric acid in the presence of an acid catalyst without additional separation and purification process to form (S)-3-hydroxy-.gamma.-butyrolactone expressed by the Formula 1, ##STR7##wherein, M represents hydrogen, alkali metal or alkali earth metal atom; R represents linear or branched alkyl group with 1.about.5 carbon atoms.