Abstract A series of hydantoin prostaglandin analogues, in which the hexamethylene moiety of the acid side chain was replaced by other spacing groups possessing either ether, sulphide and/or olefin functionality, were prepared and evaluated for platelet aggregation inhibiting activity. The 4-thia analogue 13 proved to be the most potent inhibitor (ca. 22x PGE 1) and the 3-thia-and 3-oxa-analogues, 6 and 10 respectively, are approximately ...
