| 摘要 |
<p>A compound represented by general formula (I), which is useful as a cataract remedy, wherein R1 represents optionally protected hydroxy; R2 represents lower alkyl; R3 represents hydrogen, lower alkyl, optionally protected hydroxy or lower alkoxy, provided that the lower alkyl may be substituted by optionally protected hydroxy, amino or lower alkylamino; R4 represents carboxyl which may be in the form of ester or carboxamide; and A represents alkylene.</p> |
