7-[3.alpha.-(3-hydroxy-3-hydrocarbylpropyl, or -1-propenyl, or 1-propynyl)-4-hydroxy-tetrahydro-2.beta.-furyl]-heptanoic or 4-heptenoic acids, esters or salts thereof are stable, prostaglandin-like acting agents.
7-[3.alpha.-(3-hydroxy-3-hydrocarbylpropyl,-1-propenyl or -propynyl)-4-hydroxy-tetrahydro-2.beta.-thienyl -heptanoic or 5-heptenoic acids, sulfoxides, sulfones, esters or salts thereof are stable, prostaglandin-like acting and antiasthmatic agents.