Compounds of formula (I): ##STR1## wherein: n is 4 to 8, X is CO, protected CO or CROH wherein R is hydrogen or C.sub.1-4 alkyl and wherein the OH moiety may be protected; R.sub.1 is hydrogen, or CO.sub.2 R.sub.1 represents an ester group in which the R.sub.1 moiety contains from 1 to 12 carbon atoms; R.sub.3 is hydroxy or protected hydroxy; R.sub.2 and R.sub.4 are separately hydrogen, C.sub.1-9 alkyl, C.sub.5-8 cycloalkyl, C.sub.5-8 cycloalkyl-C.sub.1-6 alkyl, phenyl, phenyl C.sub.1-6 alkyl, naphthyl, naphthyl C.sub.1-6 alkyl, any of which phenyl or naphthyl moieties may be substituted by one or more halogen, trifluoromethyl, C.sub.1-6 alkyl, C.sub.1-6 alkoxy or nitro groups; or R.sub.2 and R.sub.4 taken with the carbon atoms to which they are joined represent C.sub.5-8 cycloalkyl; A is hydrogen or a group CO.sub.2 B wherein B is hydrogen, or CO.sub.2 B represents an ester group in which the B moiety contains from 1 to 12 carbon atoms; or methyl; and salts thereof; have useful pharmacological properties including anti-gastric secretion, bronchodilator and platelet aggregration inhibition activities.