| abstract |
A process for producing optically pure (S) -3-hydroxy-gamma-butyrolactone expressed by the following formula 1 from polysaccharide source, comprising the following steps: (a) enzymatic reaction, using specific enzymes for sequential degradation, of amylopectin to oligosaccharide with alpha- (1,4) bond expressed by formula 2; wherein said enzymatic reaction is carried out by enzymatic reaction of alpha-amylase followed by enzymatic reaction of pululanase, where the remaining alpha-amylase is inactivated after enzymatic reaction of alpha-amylase before carrying out the enzymatic reaction of pululanase ( b) oxidation of the oligosaccharide, by actuating the basic anion exchange resin with an oxidant to give the (S) -3,4-dihydroxybutyl acid expressed by formula 3; and (c) subsequent esterification with alcohol in the presence of an acid catalyst to give ester of (S) -3,4-dihydroxybutyric acid expressed by formula 4; and (d) cyclisation of the ester prepared from (S) -3,4-di-hydroxybutyric acid in the presence of a catalyst without further separation and purification process to give (S) -3-hydroxy-gamma-butyrolactone expressed by the formula 1. where, M represents hydrogen, alkali metal or alkaline earth metal atom; R represents linear or branched alkyl group with 1 ~ 5 carbons. |