| 摘要 |
A compound of formula (II), or a salt or ester therof; wherein R is hydrogen or a hydrocarbon group and X is hydroxy, substituted hydroxy, mercapto, substituted mercapto, azido, cyano, halo, isothiocyanato, substituted amino or X represents the residue of a carbon nucleophile or is an activated aryl or heteroaryl group. Processes for the preparation of these compounds and pharmaceutical compositions containing them are also described. |
