| abstract |
Compounds of formula (I): <IMAGE> (I) wherein: R1-R6 are as defined in the specification; X is oxygen or sulphur; and the R6NCXR5 and OCOH moieties are trans and, when one or the other of R1 and R2 is an amino group, pharmaceutically acceptable salts thereof, a process and intermediates for preparing them, pharmaceutical compositions containing them, and their use in the treatment of mammals. |