ISOCARBACYCLINE DERIVATIVE AND PRODUCTION THEREOF

NEW MATERIAL:A compound expressed by formula I [R is formula II (R to R are H or 1-10C alkyl) or formula III (R to R are H or 1-10C alkyl; R is H, 1-10C alkyl, phenyl, etc.); R and R are H, tri-1-7C hydrocarbon silyl or a group capable of forming acetal bond or ester bond together with O atom of OH; R is H, CH3 or vinyl; R is 1-10C alkyl which may contain O, 3-10C alkenyl, 3-10C alkynyl, phenyl which may be replaced, phenoxy which may be replaced, etc.) and salt thereof. EXAMPLE:9(O)-Methano-# -prostaglandin I1 carboxymethyl ester. USE:A remedy for lesion of organ and liver reduced in action such as blood pressure lowering action, blood planet aggregation suppressing action, etc. PREPARATION:Isocarbacyclin carboxylic acids expressed by formula IV is subjected to condensation through dehydration with hydroxyacids expressed by formula V or amino acids expressed by formula VI to provide the compound expressed by formula I.