PROBLEM TO BE SOLVED: To provide a new 3-aryl-2-hydoxypropionic acid derivative, to provide a method for producing such a compound as to have usefulness for clinical conditions related to insulin resistance, to provide an intermediate for the compound, to provide a method for using the compound in treatment, and to provide a pharmaceutical composition containing the compound. SOLUTION: This compound used in the treatment comprises the new compound having formula (I) of 3-ä4-[2-(4-tert-butoxycarbonylaminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid. A pharmaceutically acceptable salt of the compound, a solvate of the compound, a crystal form of the compound, the method for producing the compound, the intermediate for the compound, the pharmaceutical preparation containing the compound, the use of the compound in the clinical conditions related to the insulin resistance are provided by using the compound, respectively. COPYRIGHT: (C)2004,JPO&NCIPI