Phosphonic acid diester derivatives

摘要

Phosphonic acid diester derivatives represented by general formula (1) which are useful as a remedy for hyperlipidemia and diabetes, an antitumour agent and a preventive or remedy for cataract, wherein R<1> represents cycloalkyl, etc.; R<2> represents hydrogen, phenyl or lower alkyl; R<3> and R<4> represent each lower alkyl; and A represents a heterocycle selected from among pyrazine, thiophene and phenyl-substituted thiazole rings.