Prostaglandin 12 analogues and their pharmaceutical compositions

Abstract

Prostaglandin I.sub.2 analogues of the formula: ##STR1## [wherein X represents trans-vinylene or an ethylene group unsubstituted or substituted by a bromine atom at the C-5 position, Y represents trans-vinylene or ethylene, R.sup.1 represents hydrogen or an alkyl group containing from 1 to 12 carbon atoms, R.sup.2 represents hydrogen or methyl or ethyl, R.sup.3 represents a single bond or an alkylene group containing from 1 to 4 carbon atoms, R.sup.4 represents hydrogen, an alkyl group containing from 1 to 8 carbon atoms, a cycloalkyl group containing from 4 to 7 carbon atoms unsubstituted or substituted by at least one alkyl group containing from 1 to 8 carbon atoms, or a phenyl or phenoxy group unsubstituted or carrying at least one substituent selected from halogen atoms, the trifluoromethyl group and alkyl groups containing from 1 to 3 carbon atoms, and the wavy line attached to the carbon atoms in positions 6, 11 and 15 depicted in the formula represents .alpha.- or .beta.-configuration or mixtures thereof] are new compounds possessing pharmacological properties typical of prostaglandins, for example PGI.sub.2, and are more stable than PGI.sub.2.