Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide with adequate sugar distribution by reacting starch which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation and cyclization sequentially under a specific condition.

Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by:

Abstract: The present invention relates to a continuous process for preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by the following Formula 1 and more particularly, to the continuous process which enables preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide having adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidatioin by running basic anion exchange resin with an oxidant to give (S)-3,4-dihydroxybutyric acid-anion exchange resin complex, dissociating the (S)-3,4-dihydroxybutyric acid from anion exchange resin complex and esterification sequentially under a specific condition.  wherein Represents linear or branched alkyl group with 1˜5 carbon atoms.

Abstract: This invention relates to a process for manufacturing an optically active (S)-3,4-epoxybutyric acid salt and more particularly, to a method for manufacturing (S)-3,4-epoxybutyric acid salt expressed by the following formula 1, wherein an optically active (S)-3-hydroxybutyrolactone is employed to undergo an economical ring-opening reaction and epoxvdation so that its chiral center is maintained in an original form, Wherein, R1 represents alkali metal atom, alkaline earth metal atom, alkylamine group or quarternary amine group.

Abstract: The present invention relates to a continuous process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process which enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation, esterification and cyclization sequentially under a specific condition.

Abstract: The present invention relates to a process for preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives economically in large quantities, by: (a) Preparing &agr;-(1,4)-linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation and esterification sequentially under a specific condition. wherein, R represents linear or branched alkyl group with 1˜5 carbon atoms.

Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-.gamma.-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-.gamma.-butyrolactone economically in large quantities, by:(a) Preparing .alpha.-(1,4) linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and(b) Performing oxidation, esterification and cyclization sequentially under a specific condition.