5-(2-Carboxythiophen-5-y l)-16-aryloxy-.alpha.-tetranor-.omega.-tetranorprostaglandins

An optically active compound of the structure ##STR25## the optical antipode and the racemic mixture thereof wherein M and X are selected from the group consisting of ##STR26## and keto;

• Z is a trans double bond or single bond;
• R is selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, cycloalkyl of from three to eight carbon atoms, phenyl, phenylalkyl of from seven to nine carbon atoms and substituted phenyl wherein said substituent if fluoro, chloro, bromo, iodo, alkyl and alkoxy of from one to six carbon atoms, and phenyl;
• L is selected from the group consisting of hydrogen and hydroxyl;
• and
• Ar is selected from the group consisting of phenyl, .alpha.-naphthyl, .beta.-naphthyl and monosubstituted phenyl wherein said substituent is selected from the group consisting of fluoro, chloro, bromo, trifluoromethyl, phenyl, and alkyl and alkoxy of from one to six carbon atoms.