| 摘要 |
Compounds of the formula (I): <CHEM> wherein: x is O, S or H2; Y is -CH2-CH2-, -CH=CH- or -C IDENTICAL C-; n is 1 to 5; R1 is C1-4 alkyl; R2 is hydrogen or C1-4alkyl; R3 is a hydroxy or protected hydroxy; R4 is C1-9 alkyl, C3-8 cycloalkyl or C3-8 cycloalkyl-C1-6 alkyl; and R5 is hydrogen or C1-6 alkyl; and salts thereof having useful pharmacological activity, compositions containing them and processes for their preparation. |
