| 摘要 |
A method for preparing (R)-3,4-epoxybutyric acid and a salt thereof is provided to obtain a desired product economically and simply by using cheap reagents without using any expensive and hard-to-handle reagents. A method for preparing (R)-3,4-epoxybutyric acid and a salt thereof comprises the steps of: (a) preparing (R)-3-hydroxy-gamma-butyrolactone represented by a formula(3) from alkyl (R)-4-chloro-3-hydroxybutyrate represented by a formula(4) using an acid catalyst or a cation exchange resin catalyst; (b) subjecting the compound of the formula(3) to ring-opening reaction using a halogenic acid such as HF, HBr, HCl, and HI and carboxylic acid such as C1-4 alkyl carboxylic acid to prepare (R)-3-acyloxy-4-halobutyric acid represented by a formula(5); and (c) subjecting the compound of the formula(3) to epoxy reaction in the presence of a base. In the formulae, R1 is C1-8 alkyl which may be substituted by a halogen compound, C1-8 alkenyl which may be substituted by a halogen compound, benzyl, or C3-6 cycloalkyl; R2 is halogen such as F, Cl, Br, and I; R3 is acyl(COCnH2n+1, wherein n is from 1 to 4); and R4 is C1-8 alkyl.
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