| 摘要 |
A process for preparing (R)-3,4-epoxybutyric acid salt/(R)-3,4-epoxybutyric acid is provided to simplify the preparation process by removing a reverse conversion process of the chiral center, increase optical purity of the compound by increasing yield of intermediates through enzyme hydrolysis, and reduce preparation costs by using inexpensive reagents. The process for preparing (R)-3,4-epoxybutyric acid salt/(R)-3,4-epoxybutyric acid comprises the steps of: (a) preparing (R)-3-hydroxy-gamma-butyrolactone represented by the general formula(3) in the reaction formula(1) by using lipase; (b) ring opening of the (R)-3-hydroxy-gamma-butyrolactone represented by the general formula(3) with halogen acid and carboxylic acid to prepare (R)-3-acyloxy-4-halobutyric acid represented by the general formula(5); and (c) performing epoxidation of the (R)-3-acyloxy-4-halobutyric acid represented by the general formula(5) in the presence of base, wherein R1 is optionally substituted C1-C8 alkyl group, optionally substituted C1-C8 alkenyl group, benzyl group or C3-C6 cycloalkyl group; R2 is a halogen group selected from F, Cl, Br and I for facilitating epoxidation; R3 is acyl group(COCnH2n=+1, n is 1-4); and R4 is C1-C8 alkyl group.
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