| 摘要 |
<p>Compounds of the formula (I) <CHEM> in which R1 represents a hydrogen atom or a hydroxyl protecting group; R2 represents a hydrogen atom, a carboxyl protecting group or a cation derived from an inorganic base or an organic base; R3 represents the group O(CH2)nR4 in which n is an integer from 2 to 6 and R4 represents a halogen atom or a hydroxy, C1-3alkoxy, C1-3 alkythio, azido, cyano, nitro or quaternary ammonium group N<+>R5R6R7X<->wherein R5 and R6 independently represent a C1-3alkyl group, R7 is a C1-2 alkyl group and X<-> is a pharmaceutically acceptable anion and metabolically labile esters, salts and solvates thereof, and processes for their production.</p> |
