A purified salt of &bgr;-hydroxyethoxy acetic acid of formula (1) having a fusion peak-top temperature detected by differential scanning calorimetry (DSC) and a purified 2-p-dioxanone of formula (2) derived from the purified salt of &bgr;-hydroxyethoxy acetic acid of formula (1).
1
(wherein in formula (1), n=1-2 , and if n=1, M is Na and/or K, and, if n=2, M is Ca and/or Mg.)
2
公式(1)的纯化的β-羟
乙氧基乙酸盐具有差示扫描量热法(
DSC)检测到的熔合峰顶温度,公式(2)的纯化的2-p-
二噁烷酮是从公式(1)的纯化的β-羟
乙氧基乙酸盐中衍生出来的。(其中在公式(1)中,n = 1-2,如果n = 1,则M为Na和/或K,如果n = 2,则M为Ca和/或Mg。)