PROBLEM TO BE SOLVED: To provide a novel furanone derivative and pharmaceuticals containing the same.SOLUTION: The formula (I). (I), where A represents -COOR1, R1 represents a hydrocarbon group which may have a hydrogen atom or a substituent, one of R2 and R3 represents a hydrocarbon group which may have a hydrogen atom or a substituent and another represents an amino group which may have a substituent and R4 represents a hydrogen atom or a halogen atom.SELECTED DRAWING: None【課題】新規なフラノン誘導体およびそれからなる医薬の提供。【解決手段】式（Ｉ）【化１】（式中、Ａは、－ＣＯＯＲ１を表わし、Ｒ１は、水素原子または置換基を有してもよい炭化水素基を表し、かつＲ２およびＲ３は、一方が水素原子または置換基を有してもよい炭化水素基、他方が置換基を有してもよいアミノ基を表す。Ｒ４は、水素原子またはハロゲン原子を表す。）【選択図】なし
