Process for preparing enantiomerically pure (S)-3-hydroxy-gamma-butyrolactone
AssigneeCouncil of Scientific and Industrial Research
InventorsMukund Keshao Gurjar, Pradeep Kumar, Anis Naim Deshmukh, Rajesh Kumar Upadhyay, Puspesh Kumar Upadhyay
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Abstract
The present invention relates to a process for the in situ preparation of optically pure (S)-3,4-dihydroxybutyric acid derivatives represented by the Formula [2] and more particularly, to a process which enables preparing optically pure (S)-3-hydroxy-γ-butyrolactone represented by Formula [1] by oxidation of α- or β-(1,4) linked disaccharide or oligosaccharide with an oxidant under basic condition to give acid and cyclization sequentially under acidic condition to give (S)-3-hydroxy-γ-butyrolactone.
Claims21
A process for the preparation of enantiomerically pure (S)-3-hydroxy-γ-butyrolactone said process comprising
- (i) dissolving a D-hexose source in an aqueous alkali solution,
- (ii) heating the solution to a temperature in the range of 40° C. to 50° C. for a period of 1 to 4 hours to obtain a dark yellow to dark red color solution,
- (iii) adding a peroxide reagent to the solution,
- (iv) raising the temperature of the solution to about 70° C. for 8 to 24 hours to obtain a reaction mixture of 3,4-dihydroxybutyric acid and glycolic acid,
- (v) cooling the reaction mixture to a temperature of about 25° C.,
- (vi) adding an acid to the reaction mixture to about pH 1.0,
- (vii) evaporating the reaction mixture of step (vi) to dryness to remove water and glycolic acid to obtain a yellow syrup,
- (viii) neutralizing the yellow syrup with a solid base,
- (ix) extracting with an organic solvent,
- (x) drying the organic layer over anhydrous sodium sulfate to obtain a residue, and
- (xi) purifying the residue over a silica gel column using a mixture of organic solvents as an eluant to obtain the pure compound (S)-3-hydroxy-γ-butyrolactone.
Dependencies are inferred from the claim text.