2,5,6,7-Tetranor-4,8-inter-m-phenylene PGI2 derivatives

Abstract: Compounds of the following formula are stable and potent analogues of prostacyclin.

Description: Field of the Invention The present invention relates to novel prostaglandin I₂ derivatives exhibiting in vivo excellent activities and duration. Background of the Invention Prostaglandin I₂ (PGI₂, prostacyclin) is a compound discovered in 1976 by J. R. Vane et al., which has called attention as a substance exerting potent platelet aggregation-inhibiting and gastric acid secretion-inhibiting activities and potent peripheral vasodilative activities after having been biosynthesized from archidonic acid via an endo peroxide (PGH₂ or PGG₂) at the vascular Wall [C & E N, Dec. 20 , 1976, p17. and S. Moncada, R. Gryglewaki, S. Bunting, J. R. Vane, Nature, 263 , 633 (1976)]. However, PGI₂ which has an exo-enol structure is extremely unstable even in neutral aqueous solution and is readily subjected to conversion to 6-oxo PGF₁ which has almost no physiological activities. Such instability is a big obstacle to its use as a drug. PGI₂ is also metabolized quickly in vivo and disadvantageously shows only short duration of physiological activities in vivo . A tremendous amount of research has been made on various derivatives for the purpose of improving the chemical stability and duration of activities in vivo of PGI₂. The inventors resolved the problems of such chemical instabilities in PGI₂ by inventing novel derivatives which have a cyclopenta (b) benzofuran ring containing a phenol ring in place of unstable exo-enol structure therein and filed a series of patent applications (See, Japanese patent application No. 36477/81, No. 32277/82, No. 144276/82, No. 124778/83, No. 134787/84, and No. 265279/87). EP-A-0060640 describes 5, 6, 7-trinor-4, 8-inter-m-phenylene PGI₂ derivatives wherein a carboxyl group or a functional derivative thereof is linked to the phenylene group by a linking group which is selected from -(CH₂) n -, -CH=CH-CH₂-, -CH₂CH=CH- or -CH₂-O-CH₂- where n is an integer of from 1 to 3. As the result of further study, it has now been found that the novel PGI₂ derivatives having the general formula (I) have strong pharmaceutical activities and in vivo excellent stability. An object of the present invention is to provide novel PGI₂ derivatives which are excellently stable and potent in vivo . Summary of the Invention The present invention relates to 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivatives having the following formula: wherein R is hydrogen, a pharmacologically acceptable cation, or an ester residue; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. Detailed Description of the Invention When R₁ in the above-given general formula (I) is an ester residue, by which we mean the residue, after removal of the OH group, of the compound R₁OH employed to form the ester, R₁ is preferably (i) a normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-R₃ wherein Z and R₃ are as defined above, and R₁ and R₂ are independent each other in the same formula ; (iii) -Z-Ar wherein Z and Ar are as defined above, and R₁ and R₂ are independent each other in the same formula ; (iv) -(CH₂CH₂O) n -CH₃ wherein n is an integer of 1 to 5 ; (v) -Z-R₆ wherein Z is as defined above, when R₂ is represented by the formula cotaining Z, R₂ and Z are independent each other, and R₆ is α-naphthyl, β-naphthyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, α-furyl, β-furyl, α-thienyl, or β-thienyl ; (vi) -C t H 2t -COOR₇ wherein C t H 2t is as defined above, when R₂ is represented by the formula cotaining C t H 2t , each C t H 2t in R₁ and R₂ is independent each other, and R₇ is methyl, ethyl or propyl ;or (vii) wherein R₈ is hydrogen or benzoyl group and R₉ is phenyl, p-bromophenyl, p-chlorophenyl, p-biphenyl, p-nitrophenyl, p-benzamidephenyl or 2-naphthyl. Examples of the pharmacologically acceptable cation in R₁ include metal cations, ammonium cations, amine cations, and quaternary ammonium cations. Particularly preferred metal cations are those derived from alkali metals, for example, lithium, sodium, potassium and alkaline earth metals, for example, magnesium and calcium. In addition, those cations from other mtals such as, for example, aluminum, zinc and iron are within the scope of the present invention. Pharmacologically acceptable amine cations are those derived from primary, secondary or tertiary amines. Examples of the suitable amines are methylamine, dimethylamine, triethylamine, ethylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dodecylamine, allylamine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and similar aliphatic, alicyclic and heterocyclic amines containing up to about 18 cabon atoms, for example, 1-methyl-piperidine, 4-ethyl morpholine, 1-isopropylpyrolidine, 2-methylpyrolidine, 4-dimethylpiperadine, 2-methylpiperadine and the like. Further examples are those amines containing water-soluble or hydrophilic groups such as, for example, mono-, di- and triethanolamines, ethyldiethylamine, N-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1, 3-propanediol, tris (hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-aminophenyl) diethanolamine, galactamine, N-methylglutamine, N-methyl glucosamine, ephedrine, phenylephrine, epinephrine, procaine and the like. Basic amino acids, specifically lysine, arginine, and the like may also be mentioned. Examples of R₁ and R₂ either or both of which are normal alkyl groups containing 1-12 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, dodecyl and the like. Further examples of R₁ and R₂ either or both of which are branched alkyl groups containing 3-14 carbon atoms include isopropyl, sec-butyl, t-butyl, iso-butyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-methylheptyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 6-methylheptyl, 1-methyloctyl, 2-methyloctyl, 3-methyloctyl, 4-methyloctyl, 5-methyloctyl, 6-methyloctyl, 7-methyloctyl, 1-methylnonyl, 1-methyldecanyl, 2-methylnonyl, 2-methyldecanyl, 1,1-dimethylbutyl, 2, 2-dimethylbutyl, 1, 1-dimethylpentyl, 2, 2-dimethylpentyl, 3, 3-dimethylpentyl, 4, 4-dimethylpentyl, 1, 1-dimethylhexyl, 2, 2-dimethylhexyl, 3, 3-dimethylhexyl, 4, 4-dimethylhexyl, 5, 5-dimethylhexyl, 1, 1-dimethylheptyl, 2, 2-dimethylheptyl, 3, 3-dimethylheptyl, 4, 4-dimethylheptyl, 5, 5-dimethylheptyl, 6, 6-dimethylheptyl, 1, 1-dimethyloctyl, 2, 2-dimethyloctyl, 3, 3-dimethyloctyl, 1, 1-dimethylnonyl, 2, 2-dimethylnonyl, 3, 3-dimethylnonyl, 1, 1-dimethyldecanyl, 2, 2-dimethyldecanyl, 3, 3-dimethyldecanyl, 1, 1, 2, 2-tetramethylpentyl, 1, 1, 3, 3-tetramethylpentyl 1, 1, 2, 2-tetramethylhexyl, 1, 1, 3, 3-tetramethylhexyl, 2, 2, 3, 3-tetramethylhexyl and the like. Examples of R₁ and R₂ either or both of which are -Z-Ar include phenyl, p-chlorophenyl, p-bromophenyl, p-fluorophenyl, 3, 4-dichlorophenyl, m-fluorophenyl, m-trifluoromethylphenyl, p-trifluoromethylphenyl, p-nitrophenyl, p-anisyl, 3, 4-dimethoxyphenyl, p-tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-propylphenyl, p-butylphenyl, 3, 4-dimethylphenyl, 2, 4-dimethylphenyl, 3-chloro-4-methylphenyl, 3-fluoro-4-methylphenyl, 4-biphenyl, p-phenoxyphenyl, 3-chloro-4-phenoxyphenyl, benzyl, p-chlorobenzyl, m-chlorobenzyl, p-methoxybenzyl, o-methoxybenzyl, p-methylbenzyl, p-ethylbenzyl, p-propylbenzyl, p-nitrobenzyl, 3, 4-dichlorobenzyl, α-methylbenzyl, α,α'-dimethylbenzyl, phenetyl, p-chlorophenetyl, p-bromophenetyl, p-fluorophenetyl, m-chlorophenetyl, m-fluorophenetyl, o-chlorophenetyl, p-methylphenetyl, p-methoxyphenetyl, 3, 4-dimethoxyphenetyl p-ethylphenetyl, α-methylphenetyl, β-methylphenetyl, α, α'-dimethylphenetyl, β, β'-dimethylphenetyl, 3-phenylpropyl, 3-(p-chlorophenyl)propyl, 3-(p-fluorophenyl)propyl, 3-(p-bromophenyl)propyl, 3-(m-chlorophenyl)propyl, 3-(3, 4-dichlorophenyl)propyl, 3-(p-tolyl)propyl, 3-(p-ethylphenyl)propyl, 4-phenylbutyl, 4-(p-chlorophenyl)butyl, 4-(3, 4-dichlorophenyl)butyl, 4-(p-tolyl)butyl, 5-phenylpentyl, α, α'-dimethyl-p-chlorophenetyl, α, α'-dimethyl-p-bromophenetyl, α, α'-dimethyl-p-fluorophenetyl, α, α'-dimethyl-m-chlorophenetyl, α, α'-dimethyl-m-bromophenetyl, α, α'-dimethyl-m-fluorophenetyl, α, α'-dimethyl-p-trifluoromethylphenetyl, α, α'-dimethyl-m-trifluoromethylphenetyl, α, α'-dimethyl-p-methylphenetyl, α, α'-dimethyl-p-methoxyphenetyl, α, α'-dimethyl-p-cyanophenetyl, 1, 1-dimethyl-3-phenylpropyl, 1, 1-dimethyl-4-phenylbutyl and the like. Examples of R₁ and R₂ either or both of which are -Z-R₃ include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclododecyl, cyclopentylmethyl, cyclohexylmethyl, cycloheptylmethyl, cyclododecylmethyl, cyclopentylethyl, cyclohexylethyl, cycloheptylethyl, cyclopentylpropyl, cyclohexylpropyl, cyclopentylbutyl, cyclohexylbutyl, cyclohexylpentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2-methylcycloheptyl, 3-methylcycloheptyl, 4-methylcyclooctyl, 2-ethylcyclopentyl, 4-methylcycloheptyl, 4-ethylcyclopentyl, 2-ethylcyclohexyl, 3-ethylcyclohexyl, 4-ethylcyclohexyl, 2-ethylcycloheptyl, 2-ethylcyclooctyl, 3-ethylcyclooctyl, 2-methylcyclopentylmethyl, 3-methylcyclopentylmethyl, 2-methylcyclohexylmethyl, 3-methylcyclohexylmethyl, 4-methylcyclohexylmethyl, 2-methylcycloheptylmethyl, 3-methylcycloheptylmethyl, 2-methylcyclooctylmethyl, 2-(2-methylcyclopentyl)ethyl, 2-(3-methylcyclopentyl)ethyl, 2-(2-methylcyclohexyl)ethyl, 2-(3-methylcyclohexyl)ethyl, 2-(4-methylcyclohexyl)ethyl, 2-(2-methylcycloheptyl)ethyl, 2-(2-methylcyclooctyl)ethyl, 3-(2-methylcyclopentyl)propyl, 3-(3-methylcyclopentyl) propyl, 3-(2-methylcyclohexyl)propyl, 3-(3-methylcyclohexyl)propyl, 3-(4-methylcyclohexyl)propyl, 5-(2-methylcyclopentyl)pentyl, 2-ethylcyclopentylmethyl, 3-ethylcyclopentylmethyl, 2-ethylcyclohexylmethyl, 3-ethylcyclohexylmethyl, 4-ethylcyclohexylmethyl, 2-ethylcycloheptylmethyl, 3-ethylcycloheptylmethyl, 2-ethylcyclooctylmethyl, 2-(2-ethylcyclopentyl)ethyl, 2-(3-ethylcyclopentyl)ethyl, 2-(4-ethylcyclohexyl)ethyl, 2-(2-ethylcycloheptyl)ethyl, 2-(2-ethylcyclooctyl)ethyl, 3-(2-ethylcyclopentyl)propyl, 3-(3-ethylcyclopentyl)propyl, 3-(2-ethylcyclohexyl)propyl, 3-(3-ethylcyclohexyl)propyl, 3-(4-ethylcyclohexyl)propyl, 5-(2-ethylcyclopentyl)pentyl, cyclopropyl, cyclobutyl, 2, 3-dimethylcyclopropyl, 2, 4-dimethylcyclobutyl, 3, 3-dimethylcyclobutyl, 1-cyclopentyl-1-methylethyl, 1-cyclohexyl-1-methylethyl, 1-cyclooctyl-1-methylethyl, 2-cyclopentyl-1, 1-dimethylethyl, 2-cyclohexyl-1, 1-dimethylethyl, 2-cyclooctyl-1, 1-dimethylethyl, 2-cyclododecyl-1, 1-dimethylethyl, 3-cyclopentyl-1, 1-dimethylpropyl, 3-cyclohexyl-1, 1-dimethylpropyl, 3-cyclooctyl-1, 1-dimethylpropyl, 4-cyclopentyl-1, 1-dimethylbutyl, 4-cyclohexyl-1, 1-dimethylbutyl, 4-cyclooctyl-1, 1-dimethylbutyl, 2-cyclopentyl-2, 2-dimethylethyl, 2-cyclohexyl-2, 2-dimethylethyl, 2-cyclooctyl-2, 2-dimethylethyl, and the like. Examples of R₂ which is -C t C 2t -C≡C-R₄ include 2-pentynyl, 3-pentynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 2-heptynyl, 3-heptynyl, 4-heptynyl, 5-heptynyl, 2-octynyl, 3-octynyl, 4-octynyl, 5-octynyl, 6-octynyl, 2-nonynyl, 3-nonynyl, 4-nonynyl, 5-nonynyl, 6-nonynyl, 7-nonynyl, 1-methyl-2-pentynyl, 1-methyl-3-pentynyl, 1-methyl-2-hexynyl, 1-methyl-3-hexynyl, 1-methyl-4-hexynyl, 1-methyl-2-heptynyl, 1-methyl-3-heptynyl, 1-methyl-4-heptynyl, 1-methyl-5-heptynyl, 1-methyl-2-octynyl, 1-methyl-3-octynyl, 1-methyl-4-octynyl, 1-methyl-5-octynyl, 1-methyl-6-octynyl, 1-methyl-2-nonynyl, 1-methyl-3-nonynyl, 1-methyl-4-nonynyl, 1-methyl-5-nonynyl, 1-methyl-6-nonynyl, 1, 1-dimethyl-2-pentynyl, 1, 1-dimethyl-3-pentynyl, 1, 1-dimethyl-2-hexynyl, 1, 1-dimethyl-3-hexynyl, 1, 1-dimethyl-4-hexynyl, 1, 1-dimethyl-2-heptynyl, 1, 1-dimethyl-3-heptynyl, 1, 1-dimethyl-4-heptynyl, 1, 1-dimethyl-5-heptynyl, 1, 1-dimethyl-2-octynyl, 1, 1-dimethyl-3-octynyl, 1, 1-dimethyl-4-octynyl, 1, 1-dimethyl-5-octynyl, 1, 1-dimethyl-2-nonynyl, 1, 1-dimethyl-3-nonynyl, 1, 1-dimethyl-4-nonynyl, 1, 1-dimethyl-5-nonynyl, 2, 2-dimethyl-3-pentynyl, 2, 2-dimethyl-3-hexynyl, 2, 2-dimethyl-4-hexynyl, 2, 2-dimethyl-3-heptynyl, 2, 2-dimethyl-4-heptynyl, and the like. Examples of R₂ which is -C t H 2t -O-R₅ include methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, n-pentyloxymethyl, n-hexyloxymethyl, 1-methoxy-1-methylethyl, 1-ethoxy-1-methylethyl, 1-methyl-1-propoxyethyl, 1-butoxy-1-methylethyl, 1-methyl-1-n-pentyloxyethyl, 1-n-hexyl-1-methylethyl, isopropoxymethyl, sec-butoxymethyl, iso-butoxymethyl, t-butoxymethyl, (1, 1-dimethylbutoxy)methyl, (1, 1-dimethyl-n-pentyloxy)methyl, (1, 1-dimethyl-n-hexyloxy)methyl, 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-butoxyethyl, 2-n-pentyloxyethyl, 2-n-hexyloxyethyl, 2-methoxy-1, 1-dimethylethyl, 2-ethoxy-1, 1-dimethylethyl, 1, 1-dimethyl-2-propoxyethyl, 2-butoxy-1, 1-dimethylethyl, 1, 1-dimethyl-2-n-pentyloxyethyl, 2-n-hexyloxy-1, 1-dimethylethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-propoxypropyl, 3-butoxypropyl, 3-n-pentyloxypropyl, 3-n-hexyloxypropyl, 3-methoxy-1, 1-dimethylpropyl, 3-ethoxy-1, 1-dimethylpropyl, 1, 1-dimethyl-3-propoxypropyl, 3-butoxy-1, 1-dimethylpropyl, 1, 1-dimethyl-3-n-pentyloxypropyl, 2-isopropoxyethyl, 2-sec-butoxyethyl, 2-t-butoxy-ethyl, 2-methoxy-1-methylethyl, 2-ethoxy-1-methylethyl, 1-methyl-2-propoxyethyl, 2-butoxy-1-methylethyl, cyclopentyloxymethyl, cyclohexyloxymethyl, 1-cyclopentyloxy-1-methylethyl, 1-cyclohexyloxy-1-methylethyl, (2, 5-dimethylcyclopentyloxy)methyl, (3, 4-dimethylcyclopentyloxy)methyl, (4-methyl-cyclohexyloxy)methyl, (2, 6-dimethylcyclohexyloxy)methyl, (2, 2, 6, 6-tetramethylcyclohexyloxy)methyl, 1-methyl-1-(3, 4-dimethylcyclopentyloxy)ethyl, 1-methyl-1-(4-methylcyclohexyloxy)ethyl, 2-(cyclopentyloxy)ethyl, 2-(cyclohexyloxy)ethyl, 2-(cyclopentyloxy)-1, 1-dimethylethyl, 2-(cyclohexyloxy)-1, 1-dimethylethyl, 3-cyclopentyloxypropyl, 3-cyclohexyloxypropyl, 3-(cyclopentyloxy)-1, 1-dimethylpropyl, 3-(cyclohexyloxy)-1, 1-dimethylpropyl, phenoxymethyl, p-chlorophenoxymethyl, m-chlorophenoxymethyl, 2, 4-dichlorophenoxymethyl, 3, 4-dichlorophenoxymethyl, p-bromophenoxymethyl, m-bromophenoxymethyl, 2, 4-dibromophenoxymethyl, 3, 4-dibromophenoxymethyl, p-fluorophenoxymethyl, m-fluorophenoxymethyl, o-fluorophenoxymethyl, p-trifluoromethylphenoxymethyl, m-trifluoromethylphenoxymethyl, o-trifluoromethylphenoxymethyl, p-nitrophenoxymethyl, p-cyanophenoxymethyl, p-phenylphenoxymethyl, p-methylphenoxymethyl, m-methylphenoxymethyl, o-methylphenoxymethyl, p-methoxyphenoxymethyl, m-methoxyphenoxymethyl, o-methoxyphenoxymethyl, 1-methyl-1-phenoxyethyl, 1-(p-chlorophenoxy)-1-methylethyl, 1-(m-chlorophenoxy)-1-methylethyl, 1-(2, 4-dichlorophenoxy)-1-methylethyl, 1-(3, 4-dichlorophenoxy)-1-methylethyl, 1-(p-bromophenoxy)-1-methylethyl, 1-(m-bromophenoxy)-1-methylethyl, 1-(2, 4-dibromophenoxy)-1-methylethyl, 1-(3, 4-dibromophenoxy)-1-methylethyl, 1-(p-fluorophenoxy)-1-methylethyl, 1-(m-fluorophenoxy)-1-methylethyl, 1-(o-fluorophenoxy)-1-methylethyl, 1-(p-trifluoromethylphenoxy)-1-methylethyl, 1-(m-trifluoromethylphenoxy)-1-methylethyl, 1-(o-trifluoromethylphenoxy)-1-methylethyl, 1-methyl-1-(p-nitrophenoxy)ethyl, 1-(p-cyanophenoxy)-1-methylethyl, 1-methyl-1-(p-phenylphenoxy)ethyl, 1-methyl-1-(p-methylphenoxy)ethyl, 1-methyl-1-(m-methylphenoxy)ethyl, 1-methyl-1-(o-methylphenoxy)ethyl, 1-(p-methoxyphenoxy)-1-methylethyl, 1-(m-methoxyphenoxy)-1-methylethyl, 1-(o-methoxyphenoxy)-1-methylethyl, 2-phenoxyethyl, 2-(p-chlorophenoxy)ethyl, 2-(m-chlorphenoxy)ethyl, 2-(2, 4-dichlorophenoxy)ethyl, 2-(3, 4-dichlorophenoxy)ethyl, 2-(p-bromophenoxy)ethyl, 2-(m-bromophenoxy)ethyl, 2-(2, 4-dibromophenoxy)ethyl, 2-(3, 4-dibromophenoxy)ethyl, 2-(p-fluorophenoxy)ethyl, 2-(m-fluorophenoxy)ethyl, 2-(o-fluorophenoxy)ethyl, 2-(p-trifluoromethylphenoxy)ethyl, 2-(m-trifluoromethylphenoxy)ethyl, 2-(o-trifluoromethylphenoxy)ethyl, 2-(p-nitrophenoxy)ethyl, 2-(p-cyanophenoxy)ethyl, 2-(p-phenylphenoxy)ethyl, 2-(p-methylphenoxy)ethyl, 2-(m-methylphenoxy)ethyl, 2-(o-methylphenoxy)ethyl, 2-(p-methoxyphenoxy)ethyl, 2-(m-methoxyphenoxy)ethyl, 2-(o-methoxyphenoxy)ethyl, 3-phenoxypropyl, 1, 1-dimethyl-3-phenoxypropyl, 1-phenoxyethyl, 1-methyl-2-phenoxyethyl, 1-methyl-3-phenoxyethyl, and the like. Examples of R₁ which is -(CH₂CH₂O) n -CH₃ include -CH₂CH₂OCH₃, -CH₂CH₂OCH₂CH₂OCH₃, -(CH₂CH₂O)₃-CH₃, -(CH₂CH₂O)₄-CH₃, -(CH₂CH₂O)₅-CH₃, and the like. Examples of R₁ which is -Z-R₆ include α-naphthyl, β-naphthyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, α-furyl, β-furyl, α-thienyl, β-thienyl, α-naphthylmethyl, β-naphthylmethyl, 2-pyridylmethyl, 3-pyridylmethyl, 4-pyridylmethyl, α-furylmethyl, β-furylmethyl, α-thienylmethyl, β-thienylmethyl, 2-(α-naphthyl)ethyl, 2-(β-naphthyl)ethyl, 2-(2-pyridyl)ethyl, 2-(3-pyridyl)ethyl, 2-(4-pyridyl)ethyl, 2-(α-furyl)ethyl, 2-(β-furyl)ethyl, 2-(α-thienyl)ethyl, 2-(β-thienyl)ethyl, 3-(α-naphthyl)propyl, 3-(β-naphthyl)propyl, 3-(2-pyridyl)propyl, 3-(3-pyridyl)propyl, 3-(4-pyridyl)propyl, 3-(α-furyl)propyl, 3-(β-furyl)propyl, 3-(α-thienyl)propyl, 3-(β-thienyl)propyl, and the like. Examples of R₁ which is -C t H 2t COOR₇ include methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, 1-methoxycarbonylethyl, 1-ethoxycarbonylethyl, 1-propoxycarbonylethyl, 2-methoxycarbonylethyl, 2-ethoxycarbonylethyl, 2-propoxycarbonylethyl, 3-methoxycarbonylpropyl, 3-ethoxycarbonylpropyl, and the like. Examples of R₁ which is include phenacyl, p-bromophenacyl, p-nitrophenacyl, p-phenylphenacyl, p-benzamidephenacyl, 2-naphthoylmethyl, α-benzoylphenacyl, and the like. The compounds having the above-mentioned general formula (I) produced by the present invention are named according to the nomenclature for prostaglandins and prostaglandin analogs proposed by N. A. Nelson et al. [N. A. Nelson, J. Med. Chem. 17 , 911, (1974) and R. A. Johnson, D. R. Morton, N. A. Nelson, Prostaglandins, 15 , 737 (1978)]. The most fundamental compounds among a series of compounds (not including the compounds of the present invention) are represented by the following formula which is numbered as shown in the figure below and named 5, 6, 7-trinor-4, 8-inter-m-phenylene PGI₂. This name is not reasonably derived from the nomenclature according to the above-mentioned references ; however, to avoid confusion the above nomenclature on the basis of 5, 6, 7-trinor-4, 8-inter-m-phenylene PGI₂ is used only in naming the compounds of the present invention which are unique PGI₂ derivatives having a cyclopenta [b] benzofuran skeleton. The above-mentioned fundamental compound is named 9-deoxy-2', 9α-epoxy-5, 6, 7-trinor-4, 8-inter-m-phenylene PGF 1α according to the nomenclature cited in the above-mentioned references. In the specification, the compounds are named, for example, 5, 6, 7-trinor-4, 8-inter-m-phenylene PGI₂ according to the simplified nomenclature as mentioned previously, but otherwise according to the nomenclature cited in the above-mentioned references. By the way, the nomenclature according to the above-mentioned references is also simplified. 1H-cyclopenta [b] benzofuran The above fundamental compound is named as a derivative substituted on a cyclopenta [b] benzofuran ring according to the IUPAC nomenclature system, namely, formally 4-[1β-(3-hydroxy-octenyl)-2-αβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuranyl) butanoic acid. However, the compounds of the present invention are named according to the simplified nomenclature as mentioned above. The naming of the compounds according to the present invention will be illustrated together with structure thereof as follows; (3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (3E)-16, 16,-dimethyl-18-oxa-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (3E)-16-methyl-15-epi-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 17, 17, 18, 18-hexadehydro-4, 8-inter-m-phenylene PGI₂ Illustrative compounds of the present invention according to the above-cited nomenclature are listed below. The compounds wherein R₂ is normal or branched alkyl group are illustrated by but not limited to: (3E)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 18, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 18, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 19, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, -dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20e-methyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20e-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20f-methyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17, 17-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19, 19-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20, 20-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20a-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b, 20b-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b, 20b-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b, 20b-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b, 20b-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20b, 20b-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c, 20c-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c, 20c-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c, 20c-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20c, 20c-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d, 20d-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d, 20d-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20d, 20d-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20e, 20e-dimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20e, 20e-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20f, 20f-dimethyl-20a, 20b, 20c, 20d, 20e, 20f, 20g-heptahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 17-trimethyl-20a, 20b, 20c, 20d, 20e, 20f-hexahomo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ The compounds wherein R₂ is -Z-Ar are illustrated by but not limited to: (3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(o-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(m-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(o-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(m-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(o-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(o-methylphenyl))-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(m-methylphenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-methylphenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-trifluoromethylphenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-nitrophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(p-cyanophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(2, 4-dichlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(3, 4-dimethylphenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-phenyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methylphenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-methylphenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methylphenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-trifluoromethylphenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-nitrophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-cyanophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4-dichlorophenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylphenyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-trifluoromethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-nitrophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-cyanophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4-dichlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(o-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(m-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(p-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(p-trifluoromethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(p-nitrophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-cyanophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4-dichlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylphenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-fluorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-trifluoromethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-nitrophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-cyanophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 4-dichlorophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-fluorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(o-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(m-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(p-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(p-trifluoromethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(p-nitrophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-cyanophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 4-dichlorophenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylphenyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-fluorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(o-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(m-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(p-methylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(p-trifluoromethylphenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(p-nitrophenyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-cyanophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 4-dichlorophenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylphenyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-phenyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-18-phenyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-18-phenyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-phenyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-19-phenyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-19-phenyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20-phenyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ The compounds wherein R₂ is -Z-R₃ are illustrated by but not limited to: (3E)-15-cyclopropyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-cyclobutyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(2-methylcyclopentyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(3-methylcyclopentyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(2, 5-dimethylcyclopentyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(3, 4-dimethylcyclopentyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(4-methylcyclohexyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(4-ethylcyclohexyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(4, 4-dimethylcyclohexyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(2, 6-dimethylcyclohexyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-cyclooctyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-15-cyclododecyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopropyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclobutyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2-methylcyclopentyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3-methylcyclopentyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-methylcyclohexyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclooctyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclododecyl-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopropyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclobutyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-methylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclooctyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclododecyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopropyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclobutyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(2-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(3-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(4-methylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclooctyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclododecyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopropyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclobutyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-methylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclooctyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclododecyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopropyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclobutyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(2-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(3-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(4-methylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyl)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclooctyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclododecyl-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopropyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclobutyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(2-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(3-methylcyclopentyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(4-methylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyl)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(2, 4, 6-trimethylcyclohexyl)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclooctyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclododecyl-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyl-17-methyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyl-17-methyl-2, 5, 6, 7, 18, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclopentyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclohexyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclopentyl-16-methyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclohexyl-16-methyl-2, 5, 6, 7, 18, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclopentyl-16, 16-dimethyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-cyclohexyl-16, 16-dimethyl-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclopentyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclohexyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclopentyl-16-methyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclohexyl-16-methyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclopentyl-16, 16-dimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-cyclohexyl-16, 16-dimethyl-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ The compounds wherein R₂ is -C t H 2t -C≡C-R₄ are illustrated by but not limited to: (3E)-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 19,19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d, 20e-pentahomo-2, 5, 6, 7-tetranor-3, 4, 19, 19, 20, 20-hexadehydro-4, 8-inter-m-phenylene-PGI₂ The compounds wherein R₂ is -C t H 2t -O-R₅ are illustrated by but not limited to: (3E)-2, 5, 6, 7, 19, 20-hexanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 19, 20-hexanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 19, 20-hexanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-methyl-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18, 18-dimethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 18-dimethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 18-dimethyl-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 18, 18-trimethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 18-trimethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 18-trimethyl-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16, 18, 18-tetramethyl-2, 5, 6, 7, 20-pentanor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7, 20-pentanor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7, 20-pentanor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7, 20-pentanor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c-trihomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b, 20c, 20d-tetrahomo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-19-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a-homo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-20a, 20b-dihomo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a-homo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a-homo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-20a, 20b-dihomo-2, 5, 6, 7-tetranor-20-oxa-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyloxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2-methylcyclopentyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3-methylcyclopentyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyloxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-methylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-propylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-butylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyloxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyloxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-methylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-propylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-butylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclopentyloxy-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(2-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(3-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 5-dimethylcyclopentyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(3, 4-dimethylcyclopentyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-cyclohexyloxy-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(4-methylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-ethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(4-propylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4-butylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(4, 4-dimethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(2, 6-dimethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyloxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyloxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-methylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-propylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-butylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyloxy-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(2-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(3-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyloxy-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(4-methylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(4-propylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-butylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyloxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclopentyloxy-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(2-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(3-methylcyclopentyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 5-dimethylcyclopentyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(3, 4-dimethylcyclopentyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-cyclohexyloxy-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(4-methylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-ethylcyclohexyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(4-propylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4-butylcyclohexyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(4, 4-dimethylcyclohexyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(2, 6-dimethylcyclohexyloxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(2, 4, 6-trimethylcyclohexyloxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methylphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-methylphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methylphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methoxyphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-methoxyphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methoxyphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methoxyphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(m-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(o-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(m-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(p-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(o-methoxyphenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-(p-methoxyphenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-16-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-fluorophenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-methoxyphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-methoxyphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-fluorophenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(o-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(m-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(p-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-methoxyphenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-methoxyphenoxy)-16-methyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-17-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-chlorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-chlorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-chlorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-bromophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-bromophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-bromophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-fluorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(m-fluorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (3E)-17-(p-fluorophenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(o-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(m-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(p-methylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(o-methoxyphenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-17-(p-methoxyphenoxy)-16, 16-dimethyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(m-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-17-(p-trifluoromethylphenoxy)-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-18-phenoxy-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-18-phenoxy-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-18-phenoxy-2, 5, 6, 7, 19, 20-hexanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-19-phenoxy-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16-methyl-19-phenoxy-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ (3E)-16, 16-dimethyl-19-phenoxy-2, 5, 6, 7, 20-pentanor-3, 4-didehydro-4, 8-inter-m-phenylene-PGI₂ and their methyl ester, ethyl ester, butyl ester, isobutyl ester, phenyl ester, benzyl ester, phenetyl ester, cyclopentyl ester, cyclohexyl ester, cyclohexylmethyl ester, furylmethyl ester, 1-carbomethoxy ester, phenacyl ester, p-bromophenacyl ester, and the like. The compounds wherein R₁ is methyl may be prepared according to processes as shown in the scheme A. The step A-1 is so-called oxidation of alcohol to aldehyde. In this step, various oxidizing agents may be used. For oxidation of the compounds having Formula I wherein R is an ester residue, the oxidizing agents such as a complex of anhydrous chromic acid and pyridine (Collins reagent), dimethylsulfoxide-dicyclohexylcarbodiimide, dimethylsulfide-chlorine, N-bromosuccinimide-chlorine and the like are preferably used. The step A-2 is carried out by condensing the aldehyde II with dimethyl phosphonate having the following formula: wherein R₂ is as defined above. The dimethyl phosphonate is usually reacted with a metal hydride such as sodium hydride, potassium hydride and the like in an ether solvent such as tetrahydrofuran, dimethoxyethane and the like to produce the corresponding salt, followed by the addition of the aldehyde II. The reaction temperature is selected from the range between -30°C to 100°C and preferably from 0°C to room temperature to give a prefered reaction. The dimethyl phosphonate used in this reaction may be prepared according to the following procedure [E. J. Cory et al., J. Am. Chem. Soc., 88 , 5654 (1966)]. The step A-3 represents the preparation of the allylalcohols IV by reducing the α, β-unsaturated ketones III. For this reduction, the reducing agents which can reduce selectively only a ketone radical without reduction of an ester radical or a double bond of α, β-unsaturated ketone are employed. For this purpose, metal hydrides, trialkoxy aluminium compounds, or dialkyl aluminium compounds are preferably used. Preferable examples of the reducing agent include zinc boron compounds (for example, Zn(BH₄)₂), combined reagents of sodium borohydride and cerium trichloride, diisobutyl (2, 6-dimethlphenoxy) aluminium, triisopropoxyaluminium and the like but is not limited to. Sodium borohydride/cerium trichloride is usually used to give a preferable result. As a solvent for this reaction, methanol is most preferably used. When the zinc borohydride compounds and the organic aluminium reducing agents are used, etheric solvents such as ether, tetrahydrofuran and dimethoxyethane are preferably used. The reaction temperature is selected from the range between -110°C to 80°C and preferably from -78°C to room temperature. The compound IV obtained according to the step A-3 is usually a mixture of 15-α isomer and 15-β isomer and used as a starting material in the step A-4 without further isolation. The step A-4 is a process for converting the radical OR to OH by transesterification of R radical by methanol whereby to produce ROMe and compounds V and VI. For this purpose, the compounds IV is dissolved in methanol, followed by the addition of appropriate base and allowed to stand at temperature of from -30°C to100°C. Anhydrous sodium carbonate, anhydrous potassium carbonate, sodium methoxide, and potassium methoxide are preferably employed as the base. The compounds obtained according to the step A-4 is usually a mixture of the 15-α isomer (V) and the 15-β isomer (VI). The 15-α isomer and the 15-β isomer are isolated by column chromatography technique (ordinary phase slica gel; when ethyl acetate/cyclohexane mixture is used as an developing eluent, preferable isolation is usually achieved). The compounds wherein R₁ is methyl may be prepared according to processes as shown in the scheme B. Illustrative preparation of the starting compound VII in the scheme B wherein R₂ is as defined above is disclosed in Japanese Patent Application No. 262021/1987. The step B-1 represents phenylselenization of α-carbon in a carboxylic acid methyl ester. This step is carried out by reacting the carboxylic acid methyl ester VII with from 3 to 4 equivalents of lithium diisopropylamide, followed by reaction with diphenyl diselenide. As a solvent for this step, tetrahydrofuran is most preferably used but not limited to. The reaction temperature after diphenyl diselenide is added to the compound VII is usually in the range between -80°C to 40°C. After the addition of diphenyl diselenide, hexamethyl phosphoric triamide (HMPA) is preferably added to the mixture. The step B-2 represents dephenylselenization. Usually, for this purpose, elimination during oxidation by hydrogen peroxide is usually used. In this case, hydrogen peroxide is usually employed in an excess amount of 35% aqueous solution. After completion of the reaction, the hydrogen peroxide is reduced with reducing agent such as dimethylsulfide, sodium thiosulfate, sodium hydrogen bisulfate and the like. The compounds wherein R₁ is hydrogen may be prepared according to processes as shown in the scheme C and the scheme D. The step C-1 and the step D-1 represent hydrolysis of the methyl ester. Usually, the compound V or VI is reacted with base in aqueous alcohol solvent such as aqueous methanol and aqueous ethanol, or aqueous ether solvent such as aqueous dioxane and aqueous tetrahydrofuran. The base includes preferably inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The reaction temperature is selected from the range between -20°C to 150°C and preferably room temperature to give a preferable reaction rate. The compounds having Formula I used in the scheme A wherein R is an ester residue, may be prepared according to processes as shown in the scheme E. Further detailed description for carring out the processes is illustrated in Examples 1 and 2. Illustrative preparation of the starting compound XI in the scheme E is disclosed in Japanese Patent Application No. 262021/1987. The compounds wherein R₁ is not hydrogen and cation but an ester residue, may be prepared by esterification of the corresponding carboxylic acid wherein R₁ is hydrogen. Many methods of esterification are known. Methods which may especially be preferred to practice the present invention include the diazoalkane method, the method by utilizing the action of active halides on silver or tertiary amine salts of carboxylic acids, and the mixed acid anhydride method. In producing the ester by the diazoalkane, the carboxylic acid may be reacted with the diazoalkane in a solvent to give a product. As the diazoalkane may be mentioned diazomethane, diazoethane, diazopropane, diazodecane and the like. The diazoalkanes, however, are not limited to those mentioned above. The second method may usually be performed by reacting a silver or tertiary amine salt of a carboxylic acid with an active halide in an aprotic polar solvent such as dimethylformamide, acetonitrile, etc. Examples of the active halides may include, but are not limited to, benzyl chloride, benzyl bromide, p-bromobenzyl bromide, p-methoxybenzyl bromide, p-phenyl benzyl bromide, phenacyl bromide, p-bromophenacyl bromide, p-nitrophenacyl bromide, α-benzoyl phenacyl bromide, etc. The third mixed acid anhydride method is most applicable. Most of the esters according to the present invention can be prepared by the mixed acid anhydride method. In this method, a salt of the carboxylic acid is reacted with ethyl chlorocarbonate, pivaloyl chloride, p-toluenesulfonic chloride to form a mixed acid anhydride. An excess amount of an alcohol represented by the formula R₁OH wherein R₁ is as defined above but does not represent hydrogen nor cation is then added to the mixed anhydride followed by heating. Specific examples of the alcohol include but are not limited to methanol, ethanol, propanol, butanol, octanol, decanol, isopropanol, 2-ethylhexanol, benzylalcohol, p-bromobenzylalcohol, phenetylalcohol, cyclopentylalcohol, cyclopentylmethylalcohol, cyclohexanol, cyclohexylmethylalcohol, 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, hydroxyacetic acid methyl ester, lactic acid methyl ester, γ-hydroxybutylic acid methyl ester, phenol, p-bromophenol, p-fluorophenol, m-chlorophenol, m-fluorophenol, 3, 4-dichlorophenol, p-(trifluoromethyl)phenol, p-methylphenol, 3, 4-dimethylphenol, p-methoxyphenol, 4-phenoxyphenol and the like. The compounds according to the present invention are illustrated by the structural formula of an optical active isomer ;however, this general formula is also to represent d, 1 and d1 isomers. The schemes A-E are also illustrated by use of the structural formula with regard to one of the optical active isomers ;however, they are applicable to any of d, 1 and d1 isomers in the same manner. The compounds according to the present invention have potent pharmacological activities such as platelet-aggregation inhibiting, platelet-adhesion inhibiting, vasodilative, gastric acid secretion inhibiting, gastric mucosa cell protecting, bronchodilative, luteo-regressive and uterotonic activities and the like. The potent platelet-aggregation inhibiting, platelet-adhesion inhibiting, vasodilative, hypolipidemic, and cholesterol and neutral lipid lowering activities can be appllied prophylactically and therapeutically to hypertention, myocardial infarction, angina pectoris, ischemic cerebral disease much as cerebral infarction and the like, TIA, peripheral circulatory disturbance (Berger's disease, Behçet's syndrome, Raynaud's disease, thrombotic thrombocytopenic purpura, arterio-venous fistula, liver diseases, and renal diseases and the like), atherosclerosis, arteriosclerosis, diabetic platelet dysfunction and neuropathy, retinal vascular obstruction hyperlipidemia, vibration diseases and the like. For the purpose, the compounds of the present invention may be administered intravenously, intra-arterially, intramuscularly, percutaneously, subcutaneously or orally. Oral or intrarectal administration needs a usual daily dose in the range of from 0.01 µg/Kg to 10 mg/Kg. The drugs are administered at one to four times a day. In the case of intravenous infution or intra-arterial injection the range of from 0.1 ng/Kg/min. to 1 µg/Kg/min. may cause good therapeutical results. In the case of usual intravenous, intramuscular or subcutaneous injection, a daily dose in the range of from 0.01 µg/Kg to 10 mg/Kg may be used at one to four times a day. Upon these administration, the dose will be determined through taking many factors including, for example, age and sex of patients ;time of administration ;conditions of the patients into account. For percutaneous administration, the dosage willvary widely depending on the dosage forms and be controlled to give a absorption of 0.001 µg/Kg - 10 mg/Kg a day per Kg body weight. The compounds according to the present invention can be used for preservation of platelets. For this purpose, the compound is added to platelet concentrate at the range of 0.01 ng - 1 µg per 1 ml of the concentrate. The compounds of the present invention are effective for the prevention of platelet aggregation and adhesion when an artificial heart and lung, an artificial kidney, an artificial liver, an artificial valve, an artificial blood vessel are employed. For this purpose, the compound is added in the dosage forms for oral administration or injection. Upon oral administration, the doses of 0.01 µg/Kg - 10 mg/Kg of the compound will result in good effects. The application of the compound to an inlet of blood flowing circuit in an artificial organ by instillation may be useful. For this purpose, the compound is given at administration rates of 0.01 ng/Kg/min. - 1 mg/Kg/min. The compounds according to the present invention are useful in treatment and prophylaxis of duodenal ulcer, gastric ulcer, chronic gastritis, digestive system disease and the like caused by non-steroidal anti-inflammatory, analgesic agents and the like. For this purpose, the compound may be orally or intravenuously administered at a dose in the range of from 0.01 µg/Kg to 10 mg/Kg per day. Adequate schedule is one to four times a day. The compounds according to the present invention are also effective for the treatment of asthma, bronchitis and respiratory disorders in pneumonia. For this purpose, the compound may be given at doses of 0.01 µg/Kg - 1 mg/Kg in the forms for oral administration or inhalation. The compounds according to the present invention are also effective for the induction of labor and the relaxation and softening of uterine cervix. For this purpose, the compound may be preferablyadministered orally, pervaginally, or intravenously by instillation. Upon oral or pervaginal administration, the compound may be given at doses of 0.01 µg/Kg - 5 mg/Kg. Upon intravenous instillation, the pharmaceutical composition containing the compound may be administered at rates of 0.01 ng/Kg/min. - 1 µg/Kg/min. The compounds of the present invention are useful in synchronizing a menstrual cycle among mammal animals (horse, bovine, hog and sheep). For this purpose, the compound may be usually given orally, pervaginally or intramascularly at doses of 0.01 µg/Kg-10 mg/Kg. The compounds of the present invention are also useful in removing congestion of nasal mucosa. For this purpose, either a solution containing from 0.1 µg/ml to 10 mg/ml of the compound in the aerosol formulations, or topically an ointment, a lotion and a liniment containing from 0.01 µg/ml - 1 mg/ml of the compound may be applied. The compounds of the present invention are useful in treating hepatitis and nephritis conditions. For this purpose, the compound may be given orally or intravenously at doses of 0.01 µg/Kg - 1 mg/Kg. The compounds according to the present invention are also useful in preventing a transfer of tumor. For this purpose, the compound may be given orally or intravenously at doses of 0.01 µg/Kg per day - 1 mg/Kg per day once to four times a day. The compounds of the present invention may be administered intravenously by instillation. For this instillation, the compound may be given at rates of 0.01 ng/Kg/min. - 100 µg/Kg/min. The compounds according to the present invention are useful as an anti-inflammatory and analgesic agent. For this purpose, the compound may be given orally or intravenously at doses of 0.01 µg/Kg/day - 1 mg/Kg/day. The compounds according to the present invention may be administered in the forms of solid compositions containing vehicles such as starch, lactose, sucrose, glucose, fine crystalline cellulose, a certain bole ; colorant ; lubricant ; binder ; disintegrating agent ; and coating. The compounds according to the present invention can be given parenterally in the forms of a sterile solution which may contain solutes, for example, sodium chloride, glucose and the like in an amount sufficient to make it isotonic. The compounds according to the present invention are stable inherently by their chemical structures, thereby are encountered with no difficulties in preparing pharmaceutical formulations, and find wide uses by a variety of routes of administration such as oral preparations (tablets, powders, granules), injections, suppositories, ointments, and lotions. Example The present invention will be illustrated by the following examples. These examples should not be construed as limiting the scope of the invention which is defined solely by the claims appended to this application. Example 1 d-(E)-3-(2α-hydroxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1) To a solution of d-2α-tetrahydropyranyloxy-1β-tetrahydropyranyloxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofurancarboxylic acid methyl ester (22.4 g, 51.8 mmoles) in dry THF at -20°C was added lithium aluminum hydride (1.97g, 51.8 mmoles) and stirred under argon at -20°C for 30 minutes. To the reaction mixture was added water (20 ml), followed by 3N hydrochloric acid (100 ml), and then extracted with ethyl acetate (500 ml, 250 ml×2). The organic layers were combined, washed with saturated aqueous sodium hydrogen carbonate (100 ml) and with brine (100 ml), dried over anhydrous magnesium sulfate, and concentrated. The resulting oily product was dissolved in dichloromethane (250 ml). To this solution then was added manganese dioxide (22.5 g, 259 mmoles), followed by the addition of 13.5 g (155 mmoles), 13.5 g (155 mmoles), and 9.0 g (104 mmoles) of manganese dioxide after 24 hours, 48 hours, and 60 hours respectively while stirring at room temperature, and stirred for further 6 hours. This reaction solution was filtered with celite by suction, and concentrated to yield 21.4 g of an oily product. To a suspension of sodium hydride (60% mineral oil dispersion, 3.52 g, 88.1 mmoles) in dry THF (60 ml) was added dry DMSO (120 ml), and cooled to -10°C. To the suspension was added a solution of dimethyl carbomethoxymethylphosphonate (16.0 g, 88.1 mmoles) in dry THF (60 ml), and stirred at 0°C for 30 minutes. To this solution then was added a solution of the above-obtained oily product in dry THF (80 ml), and stirred at 0°C for 30 minutes. To this reaction mixture was added acetic acid (5.55 ml), and concentrated. To the residue was added water (50 ml), and then extracted with ethyl acetate (200 ml, 100 ml×2). The organic layers were combined, washed with water (50 ml×2) and with brine (50 ml), dried over anhydrous magnesium sulfate, and concentrated. The resulting oily product was dissolved in methanol (300 ml), to which concentrated hydrochloric acid (1.0 ml) was added, and stirred at 50°C for 1 hours. To the reaction mixture cooled to 0°C was added sodium hydrogen carbonate (1.2g), stirred at room temperature for 30 minutes, and concentrated. To the residue was added 5% aqueous sodium chloride (100 ml), and then extracted with ethyl acetate (200 ml, 100 m1×2). The organic layers were combined, washed with brine (50 ml), driedover anhydrous magnesium sulfate, and concentrated. The residue was recrystallized to give 67.0% yield of d-(E)-3-(2α-hydroxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (10.1 g, 34.8 mmoles) as a white crystal. The mother liquid was concentrated and purified by column chromatography(silica gel : ethyl acetate/cyclohexane) to afford 3.70 g(12.8 mmoles) of d-(E)-3-(2α-hydroxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (overall yield 91.9%). The structure was confirmed by the following data : m.p. 155-156°C [α] 25 / D:+216.99 (c 0.400, MeOH) IR (KBr) :3250, 2950, 2870, 1705, 1630, 1600, 1440, 1380, 1350, 1310, 1270, 1250, 1220, 1200, 1170, 1060, 1020, 980, 900, 860, 780, 750, 720, 600 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :1.75 - 1.85(1H, m), 2.05-2.25 (3H, m), 2.65 (1H, dt, J=6.9, 13.5Hz), 3.45 (1H, t, J=8.6Hz), 3.80 (3H, s), 3.8-3.9 (1H, m), 3.95-4.0 (1H, m), 4.1-4.2 (1H, m), 5.26 (1H, ddd, J=5.1, 6.9, 8.6Hz), 6.72 (1H, d, J=15.6Hz), 6.87 (1H, t, J=7.6Hz), 7.19 (1H, d, J=7.6Hz), 7.24 (1H, d, J=7.6Hz), 7.68 (1H, d, J=15.6Hz). MASS (EI, m/e) :290 (M⁺) High resolution mass spectrum Calcd. (C₁₆H₁₈0₅, M⁺) : 290.1154 Found (M⁺) : 290.1150 Example 2 d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (2) To a solution of d-(E)-3-(2α-hydroxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (11.3 g 38.9 mmoles) in dry THF were added anhydrous triethylamine (16.3 ml, 116.7 mmoles) and trityl chloride (16.3 g, 58.4 mmoles), and heated under reflux for 2 hours. To the reaction mixture were added anhydrous pyridine (18.8 ml, 233.4 mmoles) and acetic anhydride (22.0 ml, 233.4 mmoles), which was stirred at 50°C for 4 hours, followed by at room temperature for further 14 hours. To the reaction mixture cooled to 0°C was added 3.76 N methanolic hydrochloric acid (94 ml), and stirred at room temperature for 2 hours. To this reaction mixture was added water (50 ml), and then extracted with ethyl acetate (400 ml, 200 ml×2). The organic layers were combined, washed with saturated aqueous sodium hydrogen carbonate (30 ml) and with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by column chromatography (silica gel : ethyl acetate/cyclohexane = 1/3 ∼ 1/2) to afford d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (11.1 g 33.4 mmoles, yield 86.0%). The structure was confirmed by the following data : m.p. 155-156°C (recrystallized from ethyl acetate/cyclohexane) [α] 25 / D:+264.61 (c 0.438, MeOH) IR (KBr) :3450, 2950, 2900, 2860, 1710, 1630, 1600, 1590, 1470, 1440, 1370, 1310, 1260, 1200, 1160, 1100, 1060, 1040, 1020, 980, 950, 910, 900, 860, 840, 790, 770. 750, 720, 580, 560, 490 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :1.79 (3H, s), 2.05-2.15 (1H, m), 2.25-2.35 (2H, m), 2.58 (1H, dt, J=6.1, 14.6Hz), 3.65-3.75 (3H, m), 3.80 (3H, s), 5.08 (1H, q, J=6.1Hz), 5.33 (1H, ddd, J=5.4, 6.1, 8.3Hz), 6.72 (1H, d, J=15.9 Hz), 6.86 (1H, t, J=7.3Hz), 7.19 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.69 (1H, d, J=15.9Hz). MASS (EI, m/e) :332 (M⁺) High resolution mass spectrum Calcd. (C₁₈H₂₀0₆, M⁺) : 332.1260 Found (M⁺) : 332.1258 Example 3 d-(3E)-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (3) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g 3.01 mmoles) in dry THF (15 ml) under argon atomosphere were added anhydrous pyridine (0.075 ml, 0.933 mmoles), dry DMSO (2.14 ml), trifluoroacetic acid (0.070 ml, 0.903 mmoles), and DCC (931 mg, 4.52 mmoles), and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 199 mg, 4.97 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-oxoheptylphosphonate (1.14 g, 5.12 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at 0°C for 15 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 30 minutes, to which acetic acid (0.3 ml) was added, and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (30 ml). The aqueous layers were then re-extracted with ethyl acetate (30 ml). The organic layers were combined, washed with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane=1/6) to afford 89.7% yield of d-(3E)-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.15 g, 2.70 mmoles). The structure was confirmed by the following data : [α] 25 / D:+202.25 (c 0.886, CHCl₃) IR (liquid film) :2950, 2870, 1730, 1710, 1670, 1630, 1450, 1370, 1320, 1240, 1170, 1060, 980, 950, 860, 750 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :0.8-1.1 (3H, m), 1.2 - 2.0 (6H, m), 1.73 (3H, s), 2.1 - 3.2 (5H, m), 3.6 - 3.9 (1H, m), 3.80 (3H, s), 4.9 - 5.1 (1H, m), 5.3 - 5.6 (1H, m), 6.20 (1H, d, J=15.8Hz), 6.6 - 7.3 (5H, m), 7.69 (1H, d, J=16.1Hz). MASS (EI, m/e) :426 (M⁺) Example 4 d-(3E)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (4) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g, 3.01 mmoles) in dry THF(10 ml) under argon atomosphere were added anhydrous pyridine (0.075 ml, 0.933 mmoles), dry DMSO (2.41 ml), and trifluoroacetic acid (0.070 ml, 0.903 mmoles), to which a solution of DCC (931 mg, 4.52 mmoles) in dry THF (5 ml) was added and stirred at room temperature for 3 hours. Then sodium hydride (60% mineral oil dispersion 199 mg, 5.12 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 3-methyl-2-oxoheptylphosphonate (1.21 g, 5.12 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 30 minutes, to which acetic acid (0.3 ml) was added, and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane=1/5) to afford 95.0% yield of d-(3E)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.26 g, 2.86 mmoles). The structure was confirmed by the following data : [α] 25 / D:+201.00 (c 0.996, CHCl₃) IR (liquid film) :2940, 2870, 1740, 1720, 1670, 1630, 1450, 1380, 1320, 1240, 1180, 1060, 990, 870, 780, 750 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :0.8 - 1.8 (12H, m), 1.72 (3H, s), 2.0 - 3.2 (4H, m), 3.6 - 3.9 (1H, m), 3.80 (3H, s), 4.9 - 5.1 (1H, m), 5.2 - 5.6 (1H, m), 6.27 (1H, d, J=15.6Hz), 6.6 - 7.4 (5H, m), 7.69 (1H, d, J=16.1Hz). MASS (EI, m/e) :440 (M⁺) Example 5 d-(3E, 17S)-17-methyl-15-oxo-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (5) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g, 3.01 mmoles) in dry THF (10 ml) under argon atomosphere were added anhydrous pyridine (0.073 ml, 0.964 mmoles), dry DMSO (1.1 ml), and trifluoroacetic acid (0.1 ml, 1.3 mmoles), to which a solution of DCC (744 mg, 3.61 mmoles) in dry THF (5 ml) was added and stirred at room temperature for 2.5 hours. Then sodium hydride (60% mineral oil dispersion 190 mg, 4.75 mmoles) was suspended in dry THF (10 ml), to which a solution of dimethyl (S)-4-methyl-2-oxooctylphosphonate (1.20 g, 4.78 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at 0°C for 30 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 2 hours, to which acetic acid (0.5 ml) was added, and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane=1/9) to afford 79.0% yield of d-(3E, 17S)-17-methyl-15-oxo-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.08 g, 2.38 mmoles). The structure was confirmed by the following data : IR (liquid film) :3024, 2960, 1740, 1717, 1632, 1450, 1241, 1174, 1058, 986, 864, 667 cm⁻¹ NMR (90 M Hz, CDCl₃, δ):0.9-1.0 (6H, m), 1.2-1.7 (9H, m), 1.72 (3H, s), 2.1-3.1 (3H, m), 3.6-3.8 (1H, m), 3.80 (3H, s), 5.03 (1H, q, J=5.5Hz), 5.39 (1H, m), 6.19 (1H, dd, J=0.9, 15.9Hz), 6.6-7.3 (5H, m), 7.69 (1H, d, J=15.9Hz). MASS (EI, m/e) :454 (M⁺) Example 6 d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester 11-acetate (6) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 3, 3-dimethyl-2-oxoheptylphosphonate (1.02 g, 4.08 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 20 minutes, and raised to room temperature, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane=1/5) to afford 81.4% yield of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (891 mg, 1.96 mmoles). The structure was confirmed by the following data : [α] 25 / D:+215.52 (c 0.438, CHCl₃) IR (liquid film) :3020, 2950, 2870, 1730, 1710, 1630, 1590, 1445, 1370, 1320, 1240, 1170, 1050, 980, 955, 865, 755, 665 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :0.95 (3H, t, J=5.7Hz), 0.8-1.8 (6H, m), 1.13 (6H, s), 1 73 (3H, s), 2.0-3.1 (3H, m), 3.6-3.8 (1H, m), 3.80 (3H, s), 4.9-5.1 (1H, m), 5.2-5.5 (1H, m), 6.5-7.4 (6H, m), 7.69 (1H, d, J=16.1Hz). MASS (EI, m/e) :454 (M⁺) Example 7 d-(3E)-15-oxo-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (7) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester 800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-oxo-phenylethylphosphonate (935 mg, 4.10 mmoles) in dry THF (3 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes and at room temperature for 15 minutes, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/5) to afford 70.5% yield of d-(3E)-15-oxo-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (734 mg, 1.70 mmoles). The structure was confirmed by the following data : [α] 25 / D:+266.58 (c 0.416, CHCl₃) IR (liquid film) :3020, 2950, 1730, 1710, 1665, 1620, 1445, 1370, 1320, 1240, 1170, 1010, 980, 945, 865, 750, 700 cm⁻¹ NMR (90 MHz, CDCl₃, δ) :1.74 (3H, s), 2.0-3.3 (3H, m), 3.7-3.9 (1H, m), 3.80 (3H, s) 5.0-5.6 (2H, m), 6.6-8.1 (12H, m). MASS (EI, m/e) :432 (M⁺) Example 8 d-(3E)-15-(p-chlorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (8) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atmosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles, dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles) to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-(4-chlorophenyl)-2-oxoethylphosphate (1.08 g, 4.12 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes, and raised to room temperature, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/10) to afford 71.4% yield of d-(3E)-15-(p-chlorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (801 mg, 1.72 mmoles). The structure was confirmed by the following data : [α] 25 / D:+253.57 (c 0.532, CHCl₃) IR (liquid film) :3010, 2950, 1730, 1700, 1670, 1620, 1590, 1450, 1400, 1370, 1320, 1240, 1170, 1090, 1010, 750 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.74 (3H, s), 2.1-3.2 (3H, m), 3.7-3.9 (1H, m), 3.81 (3H, s) 5.0-5.2 (1H, m), 5.3-5.5 (1H, m), 6.6-8.0 (11H, m). MASS (EI, m/e) :466 (M⁺) Example 9 d-(3E)-15-(m-fluorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (9) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-(m-fluorophenyl)-2-oxoethylphosphonate (1.01 g, 4.10 mmoles) in dry THF (3 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes and at room temperature for 15 minutes, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/10) to afford 73.0% yield of d-(3E)-15-(m-fluorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (792 mg, 1.76 mmoles). The structure was confirmed by the following data : [α] 25 / D:+257.46 (c 0.442, CHCl₃) IR (liquid film) :3024, 2954, 1738, 1715, 1673, 1630, 1609, 1589, 1487, 1450, 1375, 1323, 1243, 1218, 1176, 1056, 986, 951, 897, 866, 756, 667 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.75 (3H, s), 2.1-3.2 (3H, m), 3.7-3.9 (1H, m), 3.81 (3H, s) 5.0-5.2 (1H, m), 5.25-5.5 (1H, m), 6.6-7.8 (11H, m). MASS (EI, m/e) :450 (M⁺) Example 10 d-(3E)-15-(p-bromophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (10) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g, 3.01 mmoles) in dry THF (10ml) under argon atomosphere were added anhydrous pyridine (0.073 ml, 0.903 mmoles), dry DMSO (1.1 ml) and trifluoroacetic acid (0.07 ml, 0.903 mmoles), to which a solution of DCC (744 mg, 3.61 mmoles) in dry THF (5 ml) was added and stirred at room temperature for 2.5 hours. Then sodium hydride (60% mineral oil dispersion 175 mg, 4.38 mmoles) was suspended in dry THF (10 ml), to which a solution of dimethyl 2-(p-bromophenyl)-2-oxoethylphosphonate (1.38 g, 4.50 mmoles) in dry THF (10 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution then was added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour, to which acetic acid (0.5 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/7) to afford 65.9 % yield of d-(3E)-15-(p-bromophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.04 g, 2.04 mmoles). The structure was confirmed by the following data : [α] D : +259.82 (c 0.468, Me OH) IR (liquid film) :3028, 3018, 1734, 1673, 1624, 1589, 1450, 1437, 1400, 1377, 1323, 1245, 1205, 1178, 1071, 988, 779, 766 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.76 (3H, s), 2.1-3.2 (3H, m), 3.81 (3H, s), 3.7-3.9 (1H, m), 5.10 (1H, q, J= 8 Hz), 5.41 (1H, m), 6.8-7.9 (11H, m). MASS (EI, m/e) :510 (M⁺) Example 11 d-(3E)-15-(2, 6-difluorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester 11-acetate (11) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles) to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-(2, 6-difluorophenyl)-2-oxoethylphosphonate (1.08 g, 4.10 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour and then at room temperature for 2 hours, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/5) to afford 62.2% yield of d-(3E)-15-(2, 6-difluorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (701 mg, 1.50 mmoles). The structure was confirmed by the following data : [α] 25 / D:+241.15 (c 0.452, CHCl₃) IR (liquid film) :3026, 2954, 1740, 1717, 1667, 1626, 1593, 1466, 1452, 1375, 1323, 1282, 1238, 1176, 1035, 1007, 948, 868, 793, 756 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.75 (3H, s), 2.1-3.2 (3H, m), 3.6-3.9 (1H, m), 3.80 (3H, s), 4.9-5.2 (1H, m), 5.25-5.5 (1H, m), 6.4-7.6 (9H, m), 7.69 (1H, d, J=16.1Hz). MASS (EI, m/e) :468 (M⁺) Example 12 d-(3E)-16-methyl-15-oxo-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (12) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g, 3.01 mmoles) in dry THF (10 ml) under argon atomosphere were added anhydrous pyridine (0.12 ml, 1.48 mmoles), dry DMSO (1.1 ml), and trifluoroacetic acid (0.115 ml, 1.49 mmoles), to which a solution of DCC (744 mg, 3.61 mmoles) in dry THF (5 ml) was added and stirred at room temperature for an hour. Then sodium hydride (60% mineral oil dispersion 180 mg, 4.50 mmoles) was suspended in dry THF (10 ml), to which a solution of dimethyl 3-methyl-2-oxo-3-phenylbutylphosphonate (1.22 g, 4.52 mmoles) in dry THF (10 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour and then for 1.5 hours after the mixture was raised to room temperature , to which acetic acid (0.5 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml ), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel ethyl acetate/cyclohexane =1/9) to afford 72.2 96 yield of d-(3E)-16-methyl-15-oxo-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.03 g, 2.17 mmoles). The structure was confirmed by the following data : IR (liquid film) :2974, 2952, 1744, 1695, 1634, 1448, 1323, 1236, 1212, 1195, 1178, 1054, 1000, 953, 781, 706 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.53 (6H, s), 1.70 (3H, s), 2.1-2.9 (3H, m), 3.53 (1H, m), 3.80 (3H, s), 4.91 (1H, q, J=8Hz), 5.22 (1H, m) , 6.02 (1H, d, J=15 Hz), 6.8 - 7.4 (10H, m), 7.61 (1H, d, J=15 Hz). MASS (EI, m/e) :474 (M⁺) Example 13 d-(3E)-15-oxo-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (13) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (1.00 g, 3.01 mmoles) in dry THF (15 ml) under argon atomosphere were added anhydrous pyridine (0.081 ml, 0.100 mmoles), dry DMSO (1.50 ml), and trifluoroacetic acid (0.080 ml, 0.103 mmoles), to which a solution of DCC (850 mg, 4.13 mmoles) in dry THF (5 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 220 mg, 5.50 mmoles) was suspended in dry THF (15 ml), to which a solution of dimethyl 2-oxo-4-phenylbutylphosphonate (1.44 g, 5.63 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour, to which acetic acid (0.3 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/6) to afford 88.8% yield of d-(3E)-15-oxo-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.03 mg, 2.17 mmoles). The structure was confirmed by the following data : IR (liquid film) :3030, 2986, 2954, 1740, 1700, 1632, 1607, 1593, 1497, 1375, 1321, 1048, 988, 948, 866, 785, 750, 702 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.71 (3H, s), 2.1-3.1 (7H, m), 3.6-3,8 (1H, m), 3.90 (3H, m), 5.00 (1H, q, J=11Hz), 5.25-5.5 (1H, m), 6.18 (1H, d, J=16 Hz), 6.6-7.3 (10H, m), 7.50 (1H, d, J=16 Hz). MASS (EI, m/e) :460 (M⁺) Example 14 d-(3E)-15-cyclopentyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (14) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 5 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-cyclopentyl-2-oxoethylphosphonate (901 mg, 4.10 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour, to which acetic acid (0.3 ml) was added and concentrated. To the residue was added ethyl acetate (40ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethylacetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/6) to afford 92.5% yield of d-(3E)-15-cyclopentyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (947 mg, 2.23 mmoles). The structure was confirmed by the following data : [α] 25 / D:+206.43 (c 0.482, CHCl₃) IR (liquid film) :2950, 2880, 1740, 1720, 1670, 1630, 1550, 1450, 1380, 1320, 1240, 1180, 1060, 1030, 990, 950, 870, 840, 760 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.5 - 3.3 (12H, m), 1.72 (3H, s), 3.6 - 3.9 (1H, m), 3.80 (3H, s), 4.9 - 5.1 (1H, m), 5.2 - 5.5 (1H, m), 6.23 (1H, d, J=15.8Hz), 6.6 - 7.4 (5H, m), 7.69 (1H, d, J=16.3Hz). MASS (EI, m/e) :424 (M⁺) Example 15 d-(3E)-15-cyclohexyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (15) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2 cyclohexyl-2-oxoethylphosphonate (959 mg, 4.10 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes and then at room temperature for 15 minutes, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/6) to afford 88.4% yield of d-(3E)-15-cyclohexyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (932 mg, 2.13 mmoles). The structure was confirmed by the following data : [α] 25 / D:+206.74 (c 0.534, CHCl₃) IR (liquid film) :3020, 2930, 2850, 1740, 1720, 1660, 1630, 1590, 1540, 1450, 1370, 1320, 1240, 1170, 1060, 980, 950, 860, 750, 670cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.0 - 3.1 (14H, m), 1.71 (3H, s), 3.6 - 3.9 (1H, m), 3.81 (3H, s), 4.9 - 5.1 (1H, m), 5.3 - 5.5 (1H, m), 6.27 (1H, d, J=15.6Hz), 6.6 - 7.4 (5H, m), 7.69 (1H, d, J=16.1 Hz). MASS (EI, m/e) :438 (M⁺) Example 16 d-(3E, 16S)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (16) To a solution of d (E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl (S)-3-methyl-2-oxo-5-heptynylphosphonate (950 mg, 4.09 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes and then at room temperature for 15 minutes, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the filtrate was washed with water (30 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was passed through a short column of silica gel, and purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/5) to afford 90.0% yield of d-(3E, 16S)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-2, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (945 mg, 2.17 mmoles). The structure was confirmed by the following data: [α] 25 / D:+217.56 (c 0.410, CHCl₃) IR (liquid film) :2928, 1710, 1696, 1669, 1634, 1593, 1557, 1450, 1375, 1321, 1048, 988, 752 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.21 (3H, d, J=7.0 Hz), 1.72 (3H, s), 1.77 (3H, t, J=2.4 Hz), 2.1 - 3.2 (6H, m), 3.6 - 3.9 (1H, m), 3.80 (3H, s), 4.9 - 5.2 (1H, m), 5.3 - 5.6 (1H, m), 6.29 (1H, d, J=15.8Hz), 6.6 - 7.4 (5H, m), 7.69 (1H, d, J=16.1 Hz). MASS (EI, m/e) :436 (M⁺) Example 17 d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (17) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (5.3 ml) under argon atomosphere were added anhydrous pyridine (0.059 ml, 0.745 mmoles), dry DMSO (1.70 ml), and trifluoroacetic acid (0.055 ml, 0.703 mmoles), to which a solution of DCC (737 mg, 3.61 mmoles) in dry THF (1.3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5.3 ml), to which a solution of dimethyl 3, 3-dimethyl-2-oxo-5-heptynylphosphonate (0.889 g, 3.61 mmoles) in dry THF (4 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 2 hours, to which acetic acid (0.27 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/5) to afford 79.8% yield of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (865.5 mg 1.92 mmoles). The structure was confirmed by the following data: IR (liquid film) :2972, 1742, 1717, 1630, 1593, 1450, 1373, 1321, 1241, 1174, 1056, 988, 948, 878, 785, 748, 719, 605 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.23 (6H, s), 1.73 (3H, s), 1.77 (3H, t, J=2.6 Hz), 2.37 (2H, q, J=2.6 Hz), 2.0 - 3.1 (3H, m), 3.6 - 3.8 (1H, m), 3.80 (3H, s), 5.02 (1H, q, J=5.5 Hz), 5.3 - 5.5 (1H, m), 6.5 - 7.0 (4H, m), 7.1 - 7.3 (2H, m), 7.69 (1H, d, J=16.1 Hz). MASS (EI, m/e) :450 (M⁺) Example 18 d-(3E)-15-oxo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (18) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-oxo-4-oxaheptylphosphonate (918 mg, 4.10 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 20 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 20 minutes, and raised to room temperature, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the filtrate was washed with water (20 ml×2). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/6) to afford 78.4% yield of d-(3E)-15-oxo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (808 mg, 1.89 mmoles). The structure was confirmed by the following data : [α] 25 / D:+216.90 (c 0.568, CHCl₃) IR (liquid film) :3000, 2930, 2870, 1730, 1700, 1620, 1440, 1360, 1310, 1230, 1160, 1100, 1050, 980, 940, 860, 750, 660 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :0.96 (3H, t, J=7.3 Hz), 1.5 - 1.9 (2H, m), 1.72 (3H, s), 2.1 - 3.1 (3H, m), 3.48 (2H, t, J=6.5 Hz), 3.6 - 3.9 (1H, m), 3.80 (3H, s), 4.19 (2H, s), 5.2 - 5.5 (1H, m), 6.4 - 7.4 (6H, m), 7.69 (1H, d, J=16.1 Hz). MASS (EI, m/e) :428 (M⁺) Example 19 d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (19) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 3,3-dimethyl-2-oxo-5-oxaheptylphosphonate (1.03 g, 4.09 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for an hour, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried overanhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/5) to afford 87.2% yield of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (958 mg, 2.10 mmoles). The structure was confirmed by the following data : [α] 25 / D:+196.43 (c 0.870, CHCl₃) IR (liquid film) :2960, 2860, 1730, 1710, 1630, 1450, 1370, 1320, 1240, 1170, 1110, 1060, 980, 950, 860, 780, 750 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.0 - 1.4 (9H, m), 1.71 (3H, s), 2.1 - 3.1 (3H, m), 3.3 - 3.9 (5H, m), 3.80 (3H, s), 4.9 - 5.1 (1H, m), 5.2 - 5.6 (1H, m), 6.5 - 7.3 (6H, m), 7.69 (1H, d, J=16.3 Hz). MASS (EI, m/e) :456 (M⁺) Example 20 d-(3E)-15-oxo-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (20) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 3 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl 2-oxo-3-phenoxypropylphosphonate (1.06 g, 4.10 mmoles) in dry THF (5ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at room temperature for 30 minutes, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/5) to afford 69.1% yield of d-(3E)-15-oxo-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (769 mg, 1.66 moles). The structure was confirmed by the following data : [α] 25 / D:+220.02 (c 0.734, CHCl₃) IR (liquid film :3010, 2930, 2850, 1700, 1630, 1600, 1500, 1450, 1370, 1320, 1240, 1170, 1050, 980, 950, 910, 860, 760, 690, 670 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.72 (3H, s), 2.0 - 3.1 (3H, m), 3.5 - 3.9 (1H, m), 3.80 (3H, s), 4.9 - 5.1 (1H, m), 5.2 - 5.5 (1H, m), 6.5 - 7.5 (11H, m), 7.68 (1H, d, J=16.0 Hz) MASS (EI, m/e) :462 (M⁺) Example 21 d-(3E, 16R)-15-oxo-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (21) To a solution of d-(E)-3-(2α-acetoxy-1β-hydroxymethyl-3aβH, 8bβH-2, 3, 3a, 8b-tetrahydro-5-1H-cyclopenta [b] benzofuran)-acrylic acid methyl ester (800 mg, 2.41 mmoles) in dry THF (8 ml) under argon atomosphere were added anhydrous pyridine (0.060 ml, 0.747 mmoles), dry DMSO (1.71 ml), and trifluoroacetic acid (0.056 ml, 0.723 mmoles), to which a solution of DCC (745 mg, 3.62 mmoles) in dry THF (3 ml) was added and stirred at room temperature for 4 hours. Then sodium hydride (60% mineral oil dispersion 159 mg, 3.98 mmoles) was suspended in dry THF (5 ml), to which a solution of dimethyl (R)-2-oxo-3-phenoxybutylphosphonate (1.11 g, 4.10 mmoles) in dry THF (5 ml) was added, and stirred under argon atomosphere at room temperature for 30 minutes. To this solution was then added the above-prepared aldehyde solution by syringe while cooling with ice. The reaction mixture was stirred at 0°C for 15 minutes and then at room temperature for an hour, to which acetic acid (0.25 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the filtrate was washed with water (20 ml). The aqueous layers were then re-extracted with ethyl acetate (20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane =1/5) to afford 73.7% yield of d-(3E, 16R)-15-oxo-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂methyl ester, 11-acetate (846 mg, 1.78 mmoles). The structure was confirmed by the following data : [α] 25 / D:+240.81 (c 1.012, CHCl₃) IR (liquid film) :2980, 2950, 1730, 1700, 1630, 1600, 1580, 1490, 1440, 1370, 1320, 1230, 1170, 1120, 1060, 980, 950, 870, 800, 780, 750, 690 cm⁻¹ NMR (90 M Hz, CDCl₃, δ) :1.55 (3H, d, J=7.0 Hz), 1.72 (3H, s), 2.0-3.0 (3H, m), 3.5 - 3.7 (1H, m), 3.79 (3H, s), 4.6 - 5.1 (2H, m), 5.2 - 5.4 (1H, m), 6.4 - 7.4 (11H, m), 7.66 (1H, d, J=16.3 Hz) MASS (EI, m/e) :476 (M⁺) Example 22 d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (22) and 15-epimer thereof (23) To a solution of d-(3E)-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.12 g, 2.63 mmoles) in methanol (40 ml) was added cerous trichloride heptahydrate (1.96 g, 5.26 mmoles), to which sodium borohydride (99.5 mg, 2.63 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 30 minutes, to which saturated aqueous sodium hydrogen carbonate (5ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (30 ml) and brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol ( 25 ml ) under argon atomosphere, to which a solution ofsodium methoxide in methanol (5.22 N, 0.15 ml , 0.79 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml) , dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/ 1 ) to afford 45.4 % yield of d-(3E)-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (461 mg, 1.194 mmoles) as a less polar eluate, followed by 44.4 % Yield of d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (451 mg, 1.168 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 99 - 100°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+282.19 (c 0.910, Me OH) IR (K Br) :3450, 2950, 1720, 1700, 1630, 1610, 1450, 1320, 1290, 1280, 1250, 1200, 1160, 1090, 980, 970, 940, 920, 870, 780, 750, 620 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.91 (3H, t, J=6.6 Hz), 1.3 - 1.7 (8H, m), 2.02 (1H, ddd, J=5.5, 9.2, 13.5 Hz), 2.41 (1H, q, J=8.3 Hz), 2.71 (1H, dt, J=6.8, 13.5 Hz), 3.43 (1H, t, J=8.3 Hz), 3.80 (3H, s), 3.9 - 4.0 (1H, m), 4.13 (1H, q, J=6.3 Hz), 5.15 - 5.3 (1H, m), 5.55 - 5.6 (2H, m), 6.71 (1H, d, J=16.0 Hz), 6.84 (1H, t, J=7.4 Hz), 76.08 (1H, d, J=7.4 Hz), 7.28 (1H, d, J=7.4 Hz), 7.68 (1H, J=16.0 Hz). MASS (EI, m/e) :368 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₃₀0₅, M⁺) : 386.2093 Found (M⁺) : 386.2079 d-(3E)-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] D :+243.01 (c 0.930, Me OH) IR (liquid film) :3380, 2920, 2850, 1700, 1620, 1600, 1440, 1370, 1320, 1260, 1240, 1200, 1170, 1070, 1030, 980, 860, 750, 660 cm⁻¹ NMR (400 MHz, CDCl₃ δ) :0.91 (3H, t, J=6.7 HZ), 1.2 - 1.8 (8H, m), 2.06 (1H, ddd, J=4.9, 8.2, 13.9 Hz), 2.45 - 2.55 (1H, m), 2.68 (1H, dt, J=7.1, 13.9 Hz), 3.50 (1H, t, J=8.7 Hz), 3.80 (3H, s), 3.95 - 4.05 (1H, m), 4.13 - 4.25 (1H, m), 5.26 (1H, ddd, J=4.9, 7.1, 8.7 Hz), 5.65 - 5.75 (2H, m), 6.71 (1H, d, J=16.2 Hz), 6.85 (1H, t, J=7.5 Hz), 7.14 (1H, d, J=7.5 Hz), 7.24 (1H, d, J=7.5 Hz), 7.68 (1H, d, J=16.2 Hz). MASS (EI, m/e) :368 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₃₀0₅, M⁺) : 386.2093 Found (M⁺) : 386.2108 Example 23 d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (24) To a solution of d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (231 mg, 0.598 mmoles) in methanol (20 ml) was added 1.015 N aqueous sodium hydroxide solution (2.95 ml, 2.99 mmoles) and stirred at room temperature for 40 hours. The reaction mixture was concentrated. To the residue was added water (20 ml), then neutralized with 1.0 N hydrochloric acid (2.99 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 263 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 84.4% yield of d-(3E)-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (188 mg, 0.505 mmoles) as a white crystal. The structure was confirmed by the following data: m.p. 179 - 180°C [α] 25 / D:+285.74 (c 0.400, Me OH) IR (K Br) :3300, 2920, 2850, 1690, 1630, 1600, 1590, 1440, 1280, 1240, 1190, 1080, 1030, 980, 860, 740, 610 cm⁻¹ NMR (400 M Hz, CDCl₃ +DMSO-d₆, δ) :0.85 - 0.95 (3H, m), 1.25 - 1.7 (8H, m), 1.95 - 2.05 (1H, m), 2.3 - 2.45 (1H, m), 2.70 (1H, dt, J=6.8, 13.7 Hz), 3.41 (1H, t, J=8.6 Hz), 3.85 - 3.95 (1H, m), 4.05 - 4.15 (1H, m), 5.15 - 5.25 (1H, m), 5.55 - 5.7 (2H, m), 6.70 (1H, d, J=16.1 Hz), 6.82 (1H, t, J=7.2 Hz), 7.04 (1H, d, J=7.2 Hz), 7.23 (1H, d, J=7.2 Hz), 7.68 (1H, d, J=16.1 Hz). MASS (EI, m/e) :372 (M⁺) High resolution mass spectrum Calcd. (C₂₂H₂₈O₅, M⁺) : 372.1937 Found (M⁺) : 372.1961 Example 24 d-(3E)-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (25) To a solution of d-(3E)-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (374 mg, 0,669 mmoles) in methanol (20 ml) was added 1.015 N aqueous sodium hydroxide solution (6.69 ml 6.79 mmoles) and stirred at room temperature for 24 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (6.79 ml), and extracted with ethyl acetate (50 ml, 30 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 284 mg of crude crystalline produce. the crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 57.7% yield of d-(3E)-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (208 mg, 0.559 mmoles) as a white crystal. The structure was confirmed by the following data: m.p. 128 - 129°C [α] 25 / D:+259.45 (c 0.402, Me OH) IR (K Br) :3350, 2930, 2850, 1700, 1630, 1440, 1280, 1250, 1210, 1180, 1020, 990, 880, 860, 780, 740 cm⁻¹ NMR (400 M Hz, CDCl₃+DMSO-d₆, δ) :0.91 (3H, t, J=6.8 Hz), 1.25 - 1.65 (8H, m), 2.04 (1H, ddd, J=5.4, 8.8, 13.7 Hz), 2.4-2.5 (1H, m), 2.67 (1H, dt, J=6.8, 13.7 Hz), 3.48 (1H, t, J=8.5 Hz), 3.9 - 4.0 (1H, m), 4.1 - 4.2 (1H, m), 5.2 - 5.3 (1H, m), 5.65 - 5.75 (2H, m), 6.70 (1H, d, J=16.1 Hz), 6.84 (1H, t, J=7.3 Hz), 7.14 (1H, d, J=7.3 Hz), 7.23 (1H, d, J=7.3 Hz), 7.69 (1H, d, J=16.1 Hz). MASS (EI, m/e) :372 (M⁺) High resolution mass spectrum Calcd. (C₂₂H₂₈O₅, M⁺) : 372.1937 Found (M⁺) : 372.1935 Example 25 d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (26) and 15-epimer thereof (27) To a solution of d-(3E)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.20 g, 2.73 mmoles) in methanol (40 ml) was added cerous trichloride heptahydrate (2.03 g, 5.46 mmoles), to which sodium borohydride (103 mg, 2.73 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (30 ml) and with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily produce was dissolved in dry methanol (25 ml) under an argon atmosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.17 ml, 0.89 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (60 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 45.1% yield of d-(3E)-16-methyl-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (492 mg, 1.23 mmoles) as a less polar eluate, followed by 40.1% yield of d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (438 mg, 1.095 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+249.87 (c 0.792, Me OH) IR (liquid film) : 3370, 3010, 2950, 2920, 2860, 1700, 1630, 1600, 1590, 1440, 1370, 1320, 1270, 1250, 1210, 1170, 1030, 980, 970, 890, 860, 750, 660 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.85 - 1.0 (6H, m), 1.0 - 1.7 (7H, m), 2.03 (1H, ddd, J=5.3, 8.9, 13.8 Hz), 2.4 - 2.5 (1H, m), 2.71 (1H, dt, J=6.8, 13.8 Hz), 3.44 (1H, t, J=8.7 Hz), 3.80 (3H, s), 3.9 - 4.0 (2H, m), 5.2 - 5.3 (1H, m),d 5.6 - 5.7 (2H, m), 6.71 (1H, d, J=16.0 Hz), 6.8 - 6.9 (1H, m), 7.05 - 7.15 (1H, m), 7.24 (1H, d, J=7.3 Hz), 7.68 (1H, d, J=16.0 Hz). MASS (EI, m/e) :400 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂0₅, M⁺) : 400.2250 Found (M⁺) : 400.2276 d-(3E)-16-methyl-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+210.44 (c 0.852, Me OH) IR (liquid film) : 3400, 3030, 2970, 2940, 2880, 1700, 1630, 1600, 1590, 1450, 1320, 1220, 1180, 980, 870, 760, 670 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.85 - 1.0 (6H, m), 1.05 - 1.7 (7H, m), 2.06 (1H, ddd, J=4.9, 8.2, 13.9 Hz), 2.45 - 2.55 (1H, m), 2.69 (1H, dt, J=6.8, 13.9 Hz), 3.45 - 3.55 (1H, m), 3.80 (3H, s), 3.95 - 4.1 (2H, m), 5.2 - 5.3 (1H, m), 5.65 - 5.75 (2H, m), 6.72 (1H, d, J=16.0 Hz), 6.85 (1H, t, J=7.6 Hz), 7.1 - 7.15 (1H, m), 7.23 (1H, d, J=7.6 Hz), 7.68 (1H, d, J=16.0 Hz). MASS (EI, m/e) :400 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂0₅, M⁺) : 400.2250 Found (M⁺) : 400.2258 Example 26 d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (28) To a solution of d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (350 mg, 0.875 mmoles) in methanol (15 ml) was added 1.0 N aqueous sodium hydroxide solution (7.0 ml, 7.0 mmoles) and stirred at room temperature for 16 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (7.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, R P-8, MeOH/H₂O 1/1 ∼ 3/1) to afford 60.7% yield of d-(3E)-16-methyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (205 mg, 0.531 mmoles). The structure was confirmed by the following data: [α] 25 / D:+232.43 (c 0.632, Me OH) IR (liquid film) : 3350, 2940, 1690, 1630, 1600, 1450, 1250, 1200, 1030, 890, 860, 780, 740 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.85 - 1.0 (6H, m), 1.05 - 1.7 (7H, m), 2.0 - 2.1 (1H, m), 2.4-2.5 (1H, m), 2.65 - 2.75 (1H, m), 3.44 (1H, t, J=8.5 Hz), 3.9 - 4.0 (2H, m), 5.2 - 5.3 (1H, m), 5.55 - 5.7 (2H, m), 6.71 (1H, d, J=15.9 Hz), 6.8 - 6.9 (1H, m), 7.1-7.15 (1H, m), 7.2 - 7.3 (1H, m), 7.75 (1H, d, J=15.9 Hz). MASS (EI, m/e) :386 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₃₀0₅, M⁺) : 386.2093 Found (M⁺) : 386.2110 Example 27 d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (29) and 15-epimer thereof (30) To a solution of d-(3E, 17S)-17-methyl-20a-homo-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.02 g, 2.25 mmoles) in methanol (10ml) was added cerous trichloride heptahydrate (930 mg, 2.49 mmoles), to which sodium borohydride (108 mg, 2.84 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily produce was dissolved in dry methanol (25 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.1 ml, 0.52 mmoles) was added and stirred at room temperature for an hour. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 32.6% yield of d-(3E, 17S)-17-methyl-15-epi-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (304 mg, 0.734 mmoles) as a less polar eluate, followed by 27.7% yield of d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (258 mg, 0.623 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester IR (liquid film) : 3382, 2958, 2930, 1717, 1632, 1445, 1321, 1251, 1205, 1174, 1077, 1038, 971, 868, 748 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.91 (3H, t, J=6.7 Hz), 0.92 (3H, d, J=6.1 Hz), 1.14 - 1.50 (9H, m), 1.99 (1H, ddd, J=5.5, 9.8, 14.0 Hz), 2.36 (1H, q, J=8.6 Hz), 2.71 (1H, dt, J=6.7, 14.0 Hz), 3.39 (1H, t, J=9.1 Hz), 3.80 (3H, s), 3.90 (1H, dt, J=6.1, 9.2 Hz), 4.19 (1H, q, J=7.3 Hz), 5.19 (1H, m), 5.52 (1H, dd, J=7.3, 15.3 Hz), 5.60 (1H, dd, J=8.5, 15.3 Hz), 6.71 (1H, d, J=15.9 Hz), 6.82 (1H, t, J=7.3 Hz), 7.04 (1H, d, J=7.3 Hz), 7.22 (1H, d, J=7.3 Hz), 7.67 (1H, d, J=15.9 Hz). MASS (EI, m/e) :414 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₃₄0₅, M⁺) : 414.2407 Found (M⁺) : 414.2379 d-(3E, 17S)-17-methyl-15-epi-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester IR (liquid film) : 3392, 2958, 2930, 2874, 1700, 1632, 1450, 1323, 1278, 1251, 1207, 1178, 1042, 988, 911, 868, 733, 646 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.89 (3H, t, J=6=6.7 Hz), 0.92 (1H, d, J=6.7 Hz), 1.1 - 1.35 (8H, m), 1.56 (1H, m), 2.01 (1H, ddd, J=5.4, 6.5, 14.8 Hz), 2.41 (1H, m), 2.66 (1H, m), 3.43 (1H, t, J=8.5 Hz), 3.78 (3H, s), 3.92 (1H, m), 4.22 (1H, m), 5.20 (1H, m), 5.67 - 5.68 (2H, m), 6.69 (1H, d, J=15.9 Hz), 6.82 (1H, t, J=7.3 Hz), 7.11 (1H, d, J=6.7 Hz), 7.21 (1H, d, J=8.0 Hz), 7.67 (1H, d, J=16.5 Hz). MASS (EI, m/e) :414 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₃₄0₅, M⁺) : 414.2407 Found (M⁺) : 414.2418 Example 28 d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (31) To a solution of d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (218 mg, 0.527 mmoles) in methanol (15 ml) was added 2.0 N aqueous sodium hydroxide solution (2.5 ml, 5.0 mmoles) and stirred at room temperature for 17 hours. The reaction mixture was concentrated. To the residue was added water (20 ml), then neutralized with 1.0 N hydrochloric acid (6.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resulting crude crystalline product was recrystallized from water-methanol to afford 52.6% yield of d-(3E, 17S)-17-methyl-20a-homo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (112 mg, 0.28 mmoles) as a white crystal. The structure was confirmed by the following data: m.p. 79 - 80°C [α] 25 / D:+264.99 (c 0.100, Me OH) IR (K Br) : 3400, 2928, 1630, 1692, 1448, 1197, 870, 743 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :0.91 (3H, t, J=7.3 Hz), 0.94 (3H, d, J=6.7 Hz), 1.16 - 1.52 (9H, m), 2.06 (1H, ddd, J=4.9, 8.4, 13.4 Hz), 2.71 (1H, m) 3.47 (1H, t, J=8.1 Hz), 3.98 (1H, dt, J=6.1, 7.9 Hz), 4.24 (1H, q, J=6.7 Hz), 5.25 (1H, m), 5.60 (1H, dd, J=6.7, 15.3 Hz), 5.67 (1H, dd, J=8.5, 15.3 Hz), 6.72 (1H, d, J=15.8 Hz), 6.85 (1H, t, J=7.9 Hz), 7.11 (1H, d, J=7.3 Hz), 7.25 -7.3 (3H, m), 7.75 (1H, d, J=15.8 Hz). MASS (EI, m/e) :400 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂0₅, M⁺) : 400.2250 Found (M⁺) : 400.2274 Example 29 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (32) and 15-epimer thereof (33) To a solution of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (847 mg, 1.87 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.39 g, 3.73 mmoles), to which sodium borohydride (70.7 mg, 1.87 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution ofsodium methoxide in methanol (5.22 N, 0.11 ml, 0.57 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (40 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 44.2% yield of d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (342 mg, 0.926 mmoles) as a less polar eluate, followed by 47.3% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (366 mg, 0.884 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+265.76 (c 0.444, Me OH) IR (liquid film) : 3380, 2945, 2850, 1700, 1625, 1600, 1580, 1440, 1315, 1270, 1240, 1200, 1170, 1065, 1030, 980, 860, 750 cm⁻¹ NMR (400 MHz, CDCl₃, δ) :0.87 (3H, s), 0.91 (3H, s), 0.92 (3H, t, J=6.8 Hz), 1.2 - 1.4 (6H, m), 1.8 - 1.85 (1H, m), 2.03 (1H, ddd, J=5.2, 8.8, 13.6 Hz), 2.3 - 2.4 (1H, m), 2.45 (1H, q, J=8.6 Hz), 2.71 (1H, ddd, J=6.1, 7.4, 13.6 Hz), 3.46 (1H, t, J=8.6 Hz), 3.80 (3H, s), 3.86 (1H, d, J=6.4 Hz), 3.9 - 4.0 (1H, m), 5.23 (1H, ddd, J=5.2, 7.4, 8.6 Hz), 5.6 - 5.75 (2H, m), 6.72 (1H, d, J=16.1 Hz), 6.84 (1H, t, J=7.6 Hz), 7.09 (1H, d, J=7.6 Hz), 7.24 (1H, d, J=7.6 Hz), 7.68 (1H, d, J=16.1 Hz). MASS (EI, m/e) :414 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₃₄0₅, M⁺) : 414.2406 Found (M⁺) : 414.2406 d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 87 - 88°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+238.50 (c 0.496, Me OH) IR (K Br) : 3530, 3460, 2950, 2860, 1695, 1630, 1600, 1585, 1445, 1330, 1320, 1265, 1220, 1200, 1180, 1100, 990, 980, 960, 950, 865, 800, 780, 765, 720 cm⁻¹ NMR (400 MHz, CDCl₃, δ) :0.88 (3H, s), 0.91 (3H, s), 0.85 - 0.95 (3H, m), 1.2 - 1.4 (6H, m), 1.51 (1H, d, J=4.4 Hz), 1.66 (1H, d, J=4.9 Hz), 2.06 (1H, ddd, J=5.1, 8.5, 13.8 Hz), 2.52 (1H, q, J=8.3 Hz), 2.69 (1H, ddd, J=5.9, 7.1, 13.8 Hz), 3.51 (1H, t, J=8.3 Hz), 3.80 (3H, s), 3.85 - 3.95 (1H, m), 3.95 - 4.15 (1H, m), 5.26 (1H, ddd, J=5.1, 7.1, 8.3 Hz), 5.65 - 5.8 (2H, m), 6.72 (1H, d, J=16.1 Hz), 6.85 (1H, t, J=7.6 Hz), 7.1 - 7.15 (1H, m), 7.2 - 7.3 (1H, m), 7.68 (1H, d, J=16.1 Hz). MASS (EI, m/e) :414 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₃₄0₅, M⁺) : 414.2406 Found (M⁺) : 414.2386 Example 30 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (34) To a solution of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (261 mg, 0.61 mmoles) in methanol (25 ml) was added 1.0 N aqueous sodium hydroxide solution (6.0 ml, 6.0 mmoles) and stirred at room temperature for 24 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (6.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, R P-8, Me OH/H₂O = 3/1) to afford 66.3% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (167 mg, 0.418 mmoles). The structure was confirmed by the following data : m.p. 84 - 85°C (recrystallized from Et OH/H₂O) [α] 25 / D:+270.23 (c 0.252, Me OH) IR (K Br) : 3370, 2950, 2925, 1685, 1625, 1600, 1445, 1420, 1250, 1200, 990, 950, 860, 740 cm⁻¹ NMR (400 M Hz, CDCl₃+DMSO-d₆, δ) :0.87 (3H, s), 0.91 (3H, s), 0.92 (3H, t, J=6.8 Hz), 1.2 - 1.4 (6H, m), 2.00 (1H, ddd, J=5.8, 9.5, 13.8 Hz), 2.39 (1H, q, J=8.5 Hz), 2.70 (1H, dt, J=7.1, 13.8 Hz), 3.42 (1H, t, J=8.5 Hz), 3.82 (1H, d, J=7.3 Hz), 3.85 - 3.95 (1H, m), 5.21 (1H, ddd, J=5.8, 7.1, 8.5 Hz), 5.61 (1H, dd, J=8.5, 15.1 Hz), 5.69 (1H, dd, J=7.3, 15.1 Hz), 6.70 (1H, d, J=15.9 Hz), 6.83 (1H, t, J=7.4 Hz), 7.07 (1H, d, J=7.4 Hz), 7.23 (1H, d, J=7.4 Hz), 7.68 (1H, d, J=15.9 Hz). MASS (EI, m/e) :400 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂0₅, M⁺) : 400.2250 Found (M⁺) : 400.2258 Example 31 d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (35) and 15-epimer thereof (36) To a solution of d-(3E)-15-oxo-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (698 mg, 1.62 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.21 g, 3.24 mmoles), to which sodium borohydride (61.3 mg, 1.62 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 15 minutes , to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the Precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.093 ml, 0.486 mmoles) was added and stirred at room temperature for 4 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 47.4% yield of d-(3E)-15-phenyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (301 mg, 0.768 mmoles) as a less polar eluate, followed by 43.4% yield of d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (275 mg, 0.702 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 130 - 131°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+310.26 (c 0.604, Me OH) IR (K Br) : 3400, 3025, 2945, 2880, 1700, 1630, 1445, 1340, 1275, 1250, 1200, 1180, 1100, 1060, 1030, 990, 950, 860, 775, 740, 700 cm⁻¹ NMR (400 M Hz, CDCl₃, δ) :2.0 - 2.1 (2H, m), 2.24 (1H, d, J=3.4 Hz), 2.49 (1H, q, J=8.3 Hz), 2.68 (1H, ddd, J=6.1, 7.1, 13.7 Hz), 3.48 (1H, t, J=8.3 Hz), 3.79 (3H, s), 3.95 - 4.05 (1H, m), 5.2 - 5.3 (2H, m), 5.75 - 5.9 (2H, m), 6.70 (1H, d, J=16.1 Hz), 6.79 (1H, t, J=7.3 Hz), 7.00 (1H, d, J=7.3 Hz), 7.21 (1H, d, J=7.3 Hz), 7.3 - 7.45 (5H, m), 7.66 (1H, d, J=16.1 Hz). MASS (EI, m/e) :392 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₄0₅, M⁺) : 392.1624 Found (M⁺) : 392.1670 d-(3E)-15-phenyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 156-157°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+287.20 (c 0.430, Me OH) IR (K Br) : 3250, 2945, 1700, 1620, 1490, 1440, 1445, 1270, 1250, 1230, 1210, 1190, 1165, 1080, 1040, 1030, 990, 980, 950, 930, 875, 850, 790, 760, 700 cm⁻¹ NMR (400 MHz, CDCl₃, δ) :1.95 - 2.1 (1H, m), 2.48 (1H, q, J=8.1 Hz), 2.66 (1H, ddd, J=6.4, 7.3, 13.7 Hz), 2.84 (1H, d, J=4.9 Hz), 3.24 (1H, d, J=4.4 Hz), 3.48 (1H, t, J=8.1 Hz), 3.79 (3H, s), 3.9 - 4.05 (1H, m), 5.15 - 5.3 (2H, m), 5.78 (1H, ddd, J=1.0, 8.1, 15.5 Hz), 5.88 (1H, dd, J=5.6, 15.5 Hz), 6.69 (1H, d, J=16.1 Hz), 6.81 (1H, t, J=7.4 Hz), 7.09 (1H, d, J=7.4 Hz), 7.21 (1H, d, J=7.4 Hz), 7.25 - 7.45 (5H, m), 7.67 (1H, d, J=16.1 Hz). MASS (EI, m/e) :392 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₄0₅, M⁺) : 392.1624 Found (M⁺) : 392.1607 Example 32 d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (37) To a solution of d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (178 mg, 0.454 mmoles) in methanol (15 ml) was added 1.0 N aqueous sodium hydroxide solution (4.0 ml, 4.0 mmoles) and stirred at room temperature for 48 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (4.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 165 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 73.4% yield of d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (126 mg, 0.333 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 177 - 178.5°C [α] 25 / D:+317.41 (c 0.356, Me OH) IR (K Br) : 3350, 3030, 2970, 2930, 1680, 1625, 1600, 1490, 1440, 1320, 1300, 1275, 1245, 1200, 1080, 1070, 1030, 980, 870, 740, 700 cm⁻¹ NMR (400 M Hz, CDCl₃+DMSO-d₆, δ) :1.98 (1H, ddd, J=5.6, 9.8, 13.4 Hz), 2.35 - 2.45 (1H, m), 2.65 - 2.75 (1H, m), 3.44 (1H, t, J=9.0 Hz), 3.9 - 4.0 (1H, m), 5.65 - 5.75 (2H, m), 5.75 - 5.85 (2H, m), 6.67 (1H, d, J=15.9 Hz), 6.77 (1H, t, J=7.4 Hz), 7.00 (1H, d, J=7.4 Hz), 7.19 (1H, d, J=7.4 Hz), 7.25 - 7.45 (5H, m), 7.64 (1H, d, J=15.9 Hz). MASS (EI, m/e):378 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₂O₅, M⁺) : 378.1467 Found (M⁺) : 378.1494 Example 33 d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂methyl ester (38) and 15-epimer thereof (39) To a solution of d-(3E)-15-(p-chlorophenyl)-15-oxo-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (784 mg, 1.68 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.25 g, 3.36 mmoles), to which sodium borohydride (63.6 mg, 1.68 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 15 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (15 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under an argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.13 ml, 0.67 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (60 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated . The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 45.9 % yield of d-(3E)-15-(p-chlorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (329 mg, 0.771 mmoles) as a less polar eluate, followed by 46.1 % yield of d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (331 mg, 0.775 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 137 - 138°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+301.28 (c 0.312, Me OH) IR (K Br) : 3462, 3430, 3292, 2958, 2872, 1705, 1690, 1632, 1491, 1448, 1334, 1286, 1243, 1207, 1183, 1089, 1064, 1035, 1015, 973, 862, 816, 779, 746, 719, 557 cm⁻¹ NMR (500 M Hz, CDCl₃, δ) :2.0 - 2.1 (2H, m), 2.29 (1H, d, J=3.3 Hz), 2.45 - 2.55 (1H, m), 2.68 (1H, ddd, J=6.2, 7.0, 13.6 Hz), 3.47 (1H, t, J=8.4 Hz), 3.79 (3H, s), 3.95 - 4.05 (1H, m), 5.2 - 5.3 (2H, m), 5.75 - 5.85 (2H, m), 6.70 (1H, d, J=16.0 Hz), 6.80 (1H, t, J=7.5 Hz), 6.99 (1H, d, J=7.5 Hz), 7.22 (1H, d, J=7.5 Hz), 7.4 - 7.5 (4H, m), 7.66 (1H, d, J=16.0 Hz). MASS (EI, m/e):426 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₃Cl0₅, M⁺) : 426.1234 Found (M⁺) : 426.1234 d-(3E)-15-(p-chlorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 136-137°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+276.26 (c 0.476, Me OH) IR (K Br) : 3510, 3442, 3302, 2954, 1711, 1632, 1605, 1491, 1448, 1402, 1344, 1317, 1292, 1276, 1249, 1203, 1168, 1093, 1013, 973, 861, 806, 781, 748, 719 cm⁻¹ NMR (500 M Hz, CDCl₃, δ) :1.71 (1H, d, J=5.1 Hz), 2.0 - 2.1 (2H, m), 2.55 - 2.65 (1H, m), 2.67 (1H, ddd, J=6.2, 6.9, 13.9 Hz), 3.51 (1H, t, J=8.3 Hz), 3.79 (3H, s), 3,95 - 4.05 (1H, m), 5.2 - 5.3 (2H, m), 5.85 - 5.95 (2H, m), 6.70 (1H, d, J=16.0 Hz), 6.83 (1H, t, J=7.3 Hz), 7.07 (1H, d, J=7.3 Hz), 7.23 (1H, d, J=7.3 Hz), 7.3 - 7.4 (4H, m), 7.67 (1H, d, J=16.0 Hz). MASS (EI, m/e):426 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₃Cl0₅, M⁺) : 426.1234 Found (M⁺) : 426.1264 Example 34 d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (40) To a solution of d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (173 mg, 0.405 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 20 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, R P-8, Me OH/H₂O=3/1 ) to afford 71.9% yield of d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (120 mg, 0.291 mmoles). The structure was confirmed by the following data : m.p. 134 - 135°C (recrystallized from ethyl acetate/methylene chloride) [α] 25 / D:+284.25 (c 0.254, Me OH) IR (K Br) : 3350, 2936, 1688, 1630, 1605, 1491, 1448, 1412, 1377, 1278, 1251, 1197, 1091, 1035, 1013, 988, 866, 830, 746 cm⁻¹ NMR (500 M Hz, CDCl₃ +DMSO-d₆, δ) :2.00 (1H, ddd, J=5.1, 9.5, 13.6 Hz), 2.35 - 2.45 (1H, m), 2.70 (1H, dt, J=6.6, 13.6 Hz), 3.43 (1H, t, J=8.8 Hz), 3.93 (1H, ddd, J=6.6, 8.6, 9.5 Hz), 5.15 - 5.25 (2H, m), 5.7 - 5.8 (2H, m), 6.69 (1H, d, J=16.1 Hz), 6.78 (1H, t, J=7.3 Hz), 6.99 (1H, d, J=7.3 Hz), 7.21 (1H, d, J=7.3 Hz), 7.3 - 7.4 (4H, m), 7.68 (1H, d, J=16.1 Hz). MASS (EI, m/e):412 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₁Cl0₅, M⁺) : 412.1078 Found (M⁺) : 426.1084 Example 35 d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (41) and 15-epimer thereof (42) To a solution of d-(3E)-15-(m-fluorophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (760 mg, 1.69 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.26 g, 3.38 mmoles), to which sodium borohydride (63.9 mg, 1.69 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the precipitate was washed with ethyl acetate (15ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution ofsodium methoxide in methanol (5.22 N, 0.13 ml, 0.68 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (60 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 43.8% yield of d-(3E)-15-(m-fluorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (304 mg, 0.741 mmoles) as a less polar eluate, followed by 41.3% yield of d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (286 mg, 0.698 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 169-170°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+289.36 (c 0.282, Me OH) IR (K Br) : 3406, 2890, 1702, 1634, 1613, 1591, 1489, 1477, 1448, 1348, 1321, 1294, 1280, 1251, 1207, 1183, 1168, 1120, 1100, 1069, 1035, 1015, 994, 975, 955, 948, 864, 777, 745, 719, 694, 522 cm⁻¹ NMR (400MHz, CDCl₃, δ) :2.05 (1H, ddd, J=5.1, 8.8, 13.8Hz), 2.12 (1H, d, J=5.4Hz), 2.38 (1H, d, J=3.4Hz), 2.45-2.55 (1H, m), 2.69 (1H, ddd, J=6.4, 7.3, 13.8Hz), 3.47 (1H, t, J=8.5Hz), 3.79 (3H, s), 3.95-4.05 (1H, m), 5.2-5.3 (2H, m), 5.75-5.85 (2H, m), 6.70 (1H, d, J=15.9Hz), 6.80 (1H, t, J=7.6Hz), 6.95-7.05 (2H, m), 7.10-7.25 (3H, m), 7.35 (1H, dt, J=5.9, 7.8Hz), 7.66 (1H, d, J=15.9Hz). MASS (EI, m/e):410 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₃F0₅, M⁺) : 410.1530 Found (M⁺) : 410.1501 d-(3E)-15-(m-fluorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 161-162°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+278.15 (c 0.586, Me OH) IR (K Br) : 3440, 2956, 2886, 1700, 1632, 1593, 1485, 1448, 1346, 1317, 1280, 1251, 1207, 1181, 1166, 1127, 1096, 1071, 1038, 1013, 994, 980, 961, 948, 866, 783, 748, 696, 520 cm⁻¹. NMR (400MHz, CDCl₃, δ) :1.72 (1H, d, J=4. 9Hz), 2.07 (1H, ddd, J=4. 9, 8.3, 13.7Hz), 2.12 (1H, d, J=3.9Hz), 2.45-2.55 (1H, m), 2.68 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.52 (1H, t, J=8.3Hz), 3.79 (3H, s), 3.95-4.05 (1H, m), 5.2-5.3 (2H, m), 5.75-5.85 (2H, m), 6.71 (1H, d, J=16.1Hz), 6.83 (1H, t, J=7.6Hz), 6.95-7.03 (1H, m), 7.05-7.17 (3H, m), 7.2-7.25 (1H, m), 7.35 (1H, dt, 5.9, 7.8Hz), 7.67 (1H, d, J=16. 1Hz). MASS (EI, m/e):410 (M⁺) High resolved mass spectrum Calcd. (C₂₄H₂₃F0₅, M⁺) : 410.1530 Found (M⁺) : 410.1548 Example 36 d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (43) To a solution of d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (176 mg, 0.429 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 40 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 170 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 79.5% yield of d-(3E)-15-(m-fluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (135 mg, 0.341 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 189-190°C [α] 25 / D:+291.36 (c 0.336, Me OH) IR (K Br) : 3364, 2976, 1688, 1634, 1593, 1450, 1305, 1278, 1249, 1205, 1073, 990, 870, 746 cm⁻¹ NMR (400MHz, CDCl₃ + DMSO-d₆, δ) :2.00 (1H, ddd, J=5.9, 9.8, 13.5Hz), 2.35-2.45 (1H, m), 2.70 (1H, dt, J=6.7, 13.5 Hz), 3.44 (1H, t, J=8.8Hz), 3.85-4.0 (1H, m), 5.15-5.25 (2H, m), 5.7-5.85 (2H, m), 6.69 (1H, d, J=15.9Hz), 6.79 (1H, t. J=7.6Hz), 6.9-7.05 (2H, m), 7.15-7.25 (3H, m), 7.3-7.4 (1H, m), 7.66 (1H, d, J=15.9Hz). MASS (EI, m/e):396 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₁FO₅, M⁺) : 396.1373 Found (M⁺) : 396.1358 Example 37 d-(3E)-15-(p-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (44) and 15-epimer thereof (45) To a solution of d-(3E)-15-(p-bromophenyl)-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.0 g, 1.91 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.42 g, 3.81 mmoles), to which sodium borohydride (63 mg, 2.32 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.1 ml, 0.52 mmoles) was added and stirred at room temperature for an hour. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/2) to afford 33% yield of d-(3E)-15 (p-bromophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (306 mg, 0.60 mmoles) as a less polar eluate, followed by 31% yield of d-(3E)-15-(p-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (293 mg 0.57 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-15-(p-bromophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+253.30 (c 0.490, Me OH) IR (liquid film) : 3390, 2936, 2870, 1744, 1719, 1620, 1491, 1466, 1437, 1292, 1249, 1195, 1168, 1118, 1031, 967, 861, 760 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.96 (1H, m), 2.0-2.2 (1H, m), 2.25 (1H, m), 2.48 (1H, m), 2.68 (1H, m), 3.47 (1H, t, J=8.4Hz), 3.79 (3H, s), 4.00 (1H, m), 5.23-5.26 (2H, m), 5.78-5.79 (2H, m), 6.70 (1H, d, J=16.1Hz), 6.81 (1H, t, J=7.3Hz), 6.99 (1H, d, J=7.4Hz), 7.22 (1H, d, J=6.9Hz), 7.25 (2H, d, J=8.3Hz), 7.51 (2H, d, J=8.3Hz), 7.66 (1H, d, J=15.6Hz), MASS (EI, m/e):470 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₃0₅Br, M') : 470.0729 Found (M⁺) : 470.0703 d-(3E)-15-(p-bromophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+249.19 (c 0.500, Me OH) IR (K Br) : 3508, 3434, 2980, 1711, 1632, 1489, 1448, 1344, 1319, 1276, 1249, 1205, 1011, 973, 862, 748 cm⁻¹ NMR (90MHz, CDCl₃, δ) :1.84-2.80 (5H, m), 3.49 (1H, t, J=8.6Hz), 3.79 (3H, s), 3.95 (1H, m), 5.12-5.25 (2H, m), 5.76-5.83 (2H, m), 6.69 (1H, d, J=16.1Hz), 6.73-7.56 (7H, m), 7.67 (1H, d, J=16.1Hz). MASS (EI, m/e):470 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₃O₅Br, M⁺) : 470.0729 Found (M⁺) : 470.0736 Example 38 d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (46) and 15-epimer thereof (47) To a solution of d-(3E)-15-(2, 6-difluorophenyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (661 mg, 1.41 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.05 g, 2.82 mmoles), to which sodium borohydride (53.3 mg, 1.41 mmoles) was added after cooling to 0 °C. The solution stirred at 0 °C for 15 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atmosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.11 ml, 0.67 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 30 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane 2/1) to afford 48.2% yield of d-(3E)-15-(2, 6-difluorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (291 mg, 0.680 mmoles) as a less polar eluate, followed by 44.9% yield of d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (271 mg, 0.633 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+274.20 (c 0.314, Me OH) IR (liquid film) : 3400, 3020, 2954, 1696, 1634, 1595, 1473, 1437, 1375, 1038, 994, 866, 789, 748, 667 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.9-1.95 (1H, m), 2.05 (1H, ddd, J=4.9, 8.8, 13.7Hz), 2.45-2.55 (2H, m), 2.68 (1H, ddd, J=6.3, 7.3, 13.7Hz), 3.46 (1H, t, J=8.7Hz), 3.79 (3H, s), 3.95-4.05 (1H, m), 5.23 (1H, ddd, J=J=4.9, 7.3, 8.7Hz), 5.6-5.65 (1H, m), 5.76 (1H, dd, J=8.6, 15.2Hz), 6.02 (1H, dd, J=5.6, 15.2Hz), 6.70 (1H, d, J=15.9Hz), 6.81 (1H, t, J=7.5Hz), 6.85-6.95 (2H, m), 7.01 (1H, d, J=7.5Hz), 7.2-7.5 (2H, m), 7.67 (1H, d, J=15.9Hz). MASS (EI, m/e):428 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₂F₂0₅, M⁺) : 428.1435 Found (M⁺) : 428.1432 d-(3E)-15-(2, 6-difluorophenyl)-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 137 - 140°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+238.40 (c 0.526, Me OH) IR (K Br) : 3356, 2952, 1688, 1628, 1603, 1473, 1450, 1325, 1261, 1199, 1180, 1075, 1004, 868, 795, 746, 56 7 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.65-1.75 (1H, m), 2.06 (1H, ddd, J=4.9, 8.5, 13.7Hz), 2.4-2.55 (2H, m), 2.67 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.51 (1H, t, J=8.6Hz), 3.79 (3H, s), 3.95-4.05 (1H, m), 5.24 (1H, ddd, J=4.9, 7.3, 8.6Hz), 5.6-5.7 (1H, m), 5.80 (1H, dd, J=8.3, 15.3Hz), 6.01 (1H, dd, J=6.1, 15.3Hz), 6.70 (1H, d, J=16.1Hz), 6.84 (1H, t, J=7.5Hz), 6.9-7.0 (2H, m), 7.13 (1H, d, J=7.5Hz), 7.2-7.35 (2H, m), 7.67 (1H, d, J=16.1Hz). MASS (EI, m/e):428 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₂F₂0₅, M⁺) : 428.1435 Found (M⁺) : 428.1453 Example 39 d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (48) To a solution of d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (184 mg 0.430 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 40 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 212 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 69.8% yield of d-(3E)-15-(2, 6-difluorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (124 mg, 0.300 mmoles) as a white crystal. The structure was confirmed by the following data : M.P. 152-153°C [α] 25 / D:+268.66 (c 0.434, Me OH) IR (K Br) : 3450, 2936, 1690, 1626, 1593, 1473, 1448, 1251, 1234, 1197, 1075, 994, 868, 787, 746 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-d₆ δ) :1.95-2.05 (1H, m), 2.35-2.5 (1H, m), 2.68 (1H, dt, J=6.8, 13.7Hz), 3.43 (1H, t, J=8.8Hz), 3.85-4.0 (1H, m), 5.15-5.25 (1H, m), 5.61 (1H, d, J=7.2Hz), 5.78 (1H, dd, J=8.8, 15.1Hz), 6.09 (1H, dd, J=7.2, 15.1Hz), 6.68 (1H, d, J=16.1Hz), 6.77 (1H, t, J=7.5Hz), 6.85-6.95 (2H, m), 6.99 (1H, d, J=7.5Hz), 7.15-7.3 (2H, m), 7.66 (1H, d, J=16.1Hz). MASS (EI, m/e) :414 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₀F₂O₅, M⁺) : 414.1279 Found (M⁺) : 414.1290 Example 40 d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (49) and 15-epimer thereof (50) To a solution of d-(3E)-16 methyl-15-oxo-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.03 g, 2.17 mmoles) in methanol (40 ml) was added cerous trichloride heptahydrate (890 mg, 2.39 mmoles), to which sodium borohydride (175 mg, 4.61mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.10 ml, 0.52 mmoles) was added and stirred at room temperature for 1.5 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried overanhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane 1/2) to afford 49.8 % yield of d-(3E)-15-epi-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor 3, 4 didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (469 mg, 0.99 mmoles, recrystallization solvent : hexane/ethyl acetate) as a less polar eluate, followed by 38.2 % yield of d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (360 mg, 0.76 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+239.91 (c 0.496, Me OH) IR (liquid film) : 3364, 2972, 1702, 1632, 1605, 1448, 1251, 1205, 1176, 1035, 990, 866, 766, 700 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.30, 1.31 (each3H, s), 1.92 (1H, ddd, J=4.9, 8.8, 13.7Hz), 2.31 (1H, q, J=7.8Hz), 2.57 (1H, dt, J=6.8, 13.7Hz), 3.31 (1H, t, J=8.8Hz), 3.73 (3H, s), 4.13 (1H, m), 5.12 (1H, m), 5.49 (2H, t, J=5.9 Hz), 6.63 (1H, d, J=16.1Hz) 6.76 (1H, t, J=7.3Hz), 6.88 (1H, d, J=7.3Hz), 7.14-7.34 (6H, m), 7.60 (1H, d, J=16.1Hz). MASS (EI, m/e):434 (M⁺) High resolution mass spectrum Calcd. (C₂₇H₃₀0₅, M⁺) : 434.2093 Found (M⁺) : 434.2119 d-(3E)-16-methyl-16-phenyl-15-epi-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 146-147°C [α] 25 / D:+214.51 (c 0.248, Me OH) IR (K Br) : 3418, 3290, 2972, 1719, 1634, 1448, 1207, 1176, 1096, 982, 866, 702 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.29, 1.34 (each3H, s), 1.91 (1H, ddd, J=4.9, 8.8, 13.7Hz), 2.30 (1H, m), 2.55 (1H, m), 3.33 (1H, t, J=8.8Hz), 3.73 (3H, s), 4.16 (1H, m), 5.12 (1H, m), 5.41-5.50 (2H, m), 6.63 (1H, d, J=16.1Hz), 6.77 (1H, t, J=7.3Hz), 6.98 (1H, d, J=7.3Hz), 7.15-7.34 (6H, m), 7.58 (1H, d, J=16.1Hz). MASS (EI, m/e):434 (M⁺) High resolution mass spectrum Calcd. (C₂₇H₃₀0₅, M⁺) : 434.2093 Found (M⁺) : 434.2116 Example 41 d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (51) To a solution of d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (249 mg 0.57 mmoles) in methanol (15 ml) was added 2.0 N aqueous sodium hydroxide solution (2.5 ml, 5.0 mmoles) and stirred at room temperature for 18.5 hours. The reaction mixture was concentrated. To the residue was added water (20 ml), then neutralized with 1.0 N hydrochloric acid (10 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant crude crystalline product was recrystallized from ethyl acetate/cyclohexane to afford 64.7% yield of d-(3E)-16-methyl-16-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (155 mg, 0.369 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 184-185°C [α] 25 / D:+272.83 (c 0.162, Me OH) IR (K Br) : 3400, 2974, 1682, 1630, 1605, 1450, 1330, 1299, 1251, 1212, 988, 702 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-d6, δ) :1.36, 1.38, (each3H, s), 1.93 (1H, ddd, J=5.5, 9.8, 15.3Hz), 2.26 (1H, q, J=8.6Hz), 2.64 (1H, dt, J=7.0-15.3Hz), 3.29 (1H, t, J=8.6Hz), 3.80 (1H, dt, J=5.5, 6.1Hz), 4.18 (1H, d, J=6.1Hz), 5.14 (1H, ddd, J=5.5, 7.3, 8.5Hz), 5.50 (1H, m), 6.68 (1H, d, J=15.9Hz), 6.78-6.82 (2H, m), 7.22 (2H, m), 7.33 (2H, t, J=7.9Hz), 7.40 (2H, d, J=7.3Hz), 7.66 (1H, d, J=15.9Hz). MASS (EI, m/e):420 (M⁺) High resolution mass spectrum Calcd. (C₂₆H₂₈O₅, M⁺) : 420.1937 Found (M⁺) : 420.1934 Example 42 d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (52) and 15-epimer thereof (53) To a solution of d-(3E)-15-oxo-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (1.08 g, 2.35 mmoles) in methanol (30 ml) was added cerous trichloride heptahydrate (1.88 g, 5.04 mmoles), to which sodium borohydride (120 mg, 3.16 mmoles) was added after cooling to 0 °C. The solution stirred at 0 °C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atmosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.10 ml, 0.52 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/2) to afford 44.2% yield of d-(3E)-17-phenyl-15-epi-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (436 mg, 1.04 mmoles, recrystallization solvent : hexane/ethyl acetate) as a less polar eluate, followed by 38.3% yield of d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (378 mg, 0.90 mmoles, recrystallization solvent : hexane/ethyl acetate) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 98-99°C [α] 25 / D:+253.77 (c 0.106, Me OH) IR (K Br) : 3400, 2938, 1715, 1634, 1448, 1319, 1207, 1172, 1064, 986, 866, 746 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1,43-2.00 (3H, m), 2.34 (1H, m), 2.65-2.72 (3H, m), 2.91, (1H, m), 3.30 (1H, d. J=4.4Hz), 3.36 (1H, t, J=8.8Hz), 3.78 (3H, s), 3.85 (1H, m), 4.10 (1H, brm), 5.17 (1H, q, J=7.3Hz), 5.58 (2H, m), 6.70 (1H, d, J=16.1Hz), 6.81 (1H, t, J=7.3Hz), 7.06 (1H, d, J=6.8Hz), 7.17-7.31 (6H, m), 7.66 (1H, d, J=16Hz). MASS (EI, m/e):420(M⁺) High resolution mass spectrum Calcd. (C₂₆H₂₈0₅, M⁺) : 420.1937 Found (M⁺) : 420.1946 d-(3E)-17-phenyl-15-epi-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 138°C [α] 25 / D:+242.65 (c 0.558, Me OH) IR (K Br) : 3408, 2950, 1727, 1638, 1448, 1319, 1270, 1210, 1172, 1075, 986, 868, 750. 700 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.89 (2H, m), 1.99-2.24 (2H, m), 2.44 (1H, m), 2.63-2.81 (3H, m), 3.44 (1H, t, J=8.5Hz), 3.78 (3H, s), 3.96 (1H, brq, J=7.3Hz), 4.17 (1H, brm), 5.21 (1H, dt, J=5.5.7.3Hz), 5.66 (2H, m), 6.70 (1H, d, J=16Hz), 6.83 (1H, t, J=7.4Hz), 7.11 (1H, d, J=7.3Hz), 7.18-7.31 (6H, m), 7.67 (1H, d, J=16Hz). MASS (EI, m/e):420(M⁺) High resolution mass spectrum Calcd. (C₂₆H₂₈O₅, M⁺) : 420.1937 Found (M⁺) : 420.1916 Example 43 d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (54) To a solution of d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (310 mg 0.738 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (6.0 ml, 6.0 mmoles) and stirred at room temperature for 24 hours. The reaction mixture was concentrated. To the residue was added water (20 ml), then neutralized with 1.0 N hydrochloric acid (10 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined,washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant crude crystalline product was recrystallized from methanol/ether to afford 44.0% yield of d-(3E)-17-phenyl-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (133 mg, 0.328 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 163-164°C [α] 25 / D:+277.86 (c 0.176, Me OH) IR (K Br) : 3400, 2950, 1688, 1632, 1450, 1197, 965, 866, 746 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-d6, δ) :1.90 (1H, m), 2.07 (1H, ddd, J=5.3, 8.3, 13.7Hz), 2.48-2.79 (4H, m), 3.48 (1H, t, J=8.3Hz), 3.99 (1H, dt, J=6.4, 7.8Hz), 4.20 (1H, m), 5.26 (1H, m), 5.69 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.86 (1H, t, J=7.3Hz), 7.13 (1H, d, J=6.8Hz), 7.22-7.52 (6H, m), 7.75 (1H, d, J=16.1Hz). MASS (EI, m/e):406(M⁺) High resolution mass spectrum Calcd. (C₂₅H₂₆O₅, M⁺) : 406.1718 Found (M⁺) : 406.1718 Example 44 d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (55) and 15-epimer thereof (56) To a solution of d-(3E)-15-cyclopentyl-15-oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (907 mg, 2.14 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.59 g, 4.28 mmoles), to which sodium borohydride (81.0 mg, 2.14 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 15 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.16 ml, 0.84 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with saturated aqueous sodium chloride (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Rober Column, Merck (silica gel : ethyl acetate/cyclohexane 2/1) to afford 44.2% yield of d-(3E)-15-cyclopentyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (363 mg, 0.945 mmoles) as a less polar eluate, followed by 37.2% yield of d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (306 mg 0.797 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 141-142°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+291.35 (c 0.266, Me OH) IR (K Br): 3320, 2950, 2914, 2870, 1717, 1630, 1605, 1591, 1475, 1448, 1346, 1319, 1270, 1255, 1205, 1170, 1083, 1062, 1029, 988, 971, 951, 868, 777, 746, 719 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.2-2.1 (11H, m), 2.3-2.5 (2H, m), 2.71 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.45 (1H, t, J=8.7Hz), 3.80 (3H, s), 3.9-4.0 (2H, m), 5.23 (1H, ddd, J=5.4, 7.3, 8.7Hz), 5.55-5.7 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.1Hz), 7.09 (1H, d, J=7.1Hz), 7.23 (1H, d, J=7.1Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):384 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₈O₅, M⁺) : 384.1937 Found (M⁺) : 384.1965 d-(3E)-15-cyclopentyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 133.5-134°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+264.36 (c 0.564, Me OH) IR (K Br): 3532, 3492, 3304, 2954, 2904, 2868, 1705, 1634, 1448, 1342, 1313, 1276, 1249, 1205, 1187, 1166, 1091, 1027, 975, 866, 743 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.2-1.85 (10H, m), 1.95-2.1 (2H, m), 2.45-2.55 (1H, m), 2.68 (1H, ddd, J=5.9, 7.3, 14.2Hz), 3.50 (1H, t, J=8.6Hz), 3.80 (3H, s), 3.9-4.05 (2H, m), 5.26 (1H, ddd, J=4.9, 7.3, 8.6Hz) 5.65-5.75 (2H, m), 6.72 (1H, d, J=16.1Hz) 6.86 (1H, t, J=7.6Hz), 7.14 (1H, t, J=7.6Hz), 7.24 (1H, d, J=7.6Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):384 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₈O₅, M⁺) : 384.1937 Found (M⁺) : 384.1963 Example 45 d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (57) To a solution of d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (195 mg 0.501 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 45 hours. The reaction mixture was concentrated. To the residue wasadded water (15 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20ml). The organic layers were combined, washed with water (20 ml) and with brine (20ml), dried over anhydrous magnesium sulfate, and concentrated to give 187 mg of crude crystalline product. The crude crystalline product was recrystallized from Me OH/n-hexane to afford 69.8% yield of d-(3E)-15-cyclopentyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (79 mg, 0.278 mmoles) as a white crystal. The structure was confirmed by the following data: m.p.178.5-179.5°C [α] 25 / D:+295.28 (c 0.276, Me OH) IR (K Br): 3310, 2958, 2870, 1692, 1630, 1607, 1450, 1415, 1344, 1311, 1278, 1251, 1210, 1102, 1077, 1035, 973, 866, 746 cm⁻¹ NMR (500MHz, CDCl₃ +DMSO-d₆, δ) :1.25-2.05 (10H, m), 2.3-2.4 (1H, m), 2.65-2.75 (1H, m), 3.41 (1H, t, J=9.0Hz), 3.85-3.95 (2H, m), 5.15-5.25 (1H, m), 5.55-5.65 (2H, m), 6.79 (1H, d, J=16.1Hz), 6.83 (1H, t, J=7.5Hz), 7.07 (1H, d, J=7.5Hz), 7.23 (1H, d, J=7.5Hz), 7.67 (1H, d, J=16.1Hz). MASS (EI, m/e):370 (M⁺) High resolution mass spectrum Calcd. (C₂₂H₂₆O₅, M⁺) : 370.1780 Found (M⁺) : 370.1758 Example 46 d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (58) and 15-epimer thereof (59) To a solution of d (3E) 15 cyclohexyl-15 oxo-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (870 mg, 1.99 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.48 g, 3.98 mmoles), to which sodium borohydride (75.3 mg, 1.99 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (30 ml) and with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.15 ml, 0.80 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 30 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 46.8% yield of d-(3E)-15-cyclohexyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (371 mg, 0.932 mmoles) as a less polar eluate, followed by 37.4% yield of d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (296 mg 0.744 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 146-146.5°C(recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+295.59 (c 0.318, Me OH) IR (K Br): 3400, 2930, 2860, 1710, 1695, 1630, 1600, 1590, 1440, 1320, 1280, 1250, 1220, 1200, 1180, 1090, 1030, 990, 970, 950, 890, 860, 780, 750 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.9-1.5 (6H, m), 1.65-1.95 (6H, m), 2.03 (1H, ddd, J=4.9, 9.0, 13.9Hz), 2.25-2.5 (2H, m), 2.70 (1H, dt, J=6.8, 13.9Hz), 3.46 (1H, t, J=8.5Hz), 3.80 (3H, s), 3.85-4.0 (2H, m), 5.2-5.3 (1H, m), 5.55-5.7 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.3 Hz), 7.10 (1H, d, J=7.3Hz), 7.24 (1H, d, J=7.3Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):398(M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₀O₅, M⁺) : 398.2093 Found (M⁺) : 398.2136 d-(3E)-15-cyclohexyl-15-epi-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester M.P. 134-135°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+253.57 (c 0.504, Me OH) IR (K Br): 3400, 2925, 2850, 1720, 1680, 1630, 1600, 1440, 1320, 1220, 1160, 1080, 1000, 890, 860, 750 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.9-1.5 (6H, m), 1.55-1.9 (7H, m), 2.07 (1H, ddd, J=5.2, 8.3, 13.8Hz), 2.45-2.55 (1H, m), 2.68 (1H, ddd, J=5.9, 7.2, 13.8Hz), 3.51 (1H, t, J=8.6Hz), 3.80 (3H, s), 3.85-4.05 (2H, m), 5.26 (1H, ddd, J=5.2, 7.2, 8.6Hz), 5.6-5.75 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.86 (1H, t, J=7.6Hz), 7.14 (1H, d, J=7.6Hz), 7.24 (1H, d, J=7.6Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):398 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₀O₅, M⁺) : 398.2093 Found (M⁺) : 398.2065 Example 47 d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (60) To a solution of d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (183 mg, 0.460 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 24 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 198 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/Me OH to afford 70.1% yield of d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (125 mg, 0.326 mmoles) as a white crystal. The structure was confirmed by the following data: m.p. 213-214°C [α] 25 / D:+275.75 (c 0.438, Me OH) IR (K Br): 3400, 2920, 2850, 1680, 1630, 1450, 1300, 1280, 1250, 1200, 1080, 1100, 1030, 980, 970, 950, 900, 860, 780, 750 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-d₆, δ) :0.9-1.5 (6H, m), 1.65-1.8 (4H, m), 1.9-2.05 (2H, m), 2.3-2.4 (1H, m), 2.65-2.75 (1H, m), 3.35-3.45 (1H, m), 3.75-3.95 (2H, m), 5.15-5.25 (1H, m), 5.55-5.65 (2H, m), 6.68 (1H, d, J=16.1Hz), 6.83 (1H, t, J=7.3Hz), 7.08 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.66 (1H, d, J=16.1Hz). MASS (EI, m/e):384(M⁺) High recrystallized mass spectrum Calcd. (C₂₃H₂₈O₅, M⁺) : 384.1937 Found (M⁺) : 384.1955 Example 48 d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (61) and 15-epimer thereof (62) To a solution of d-(3E, 16S)-16-methyl-15-oxo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (910 mg, 2.09 mmoles) in methanol (30 ml) was added cerous trichloride heptahydrate (1.56 g, 4.18 mmoles), to which sodium borohydride (79.0 mg, 2.09 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 15 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (40 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (30 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (25 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.16 ml, 0.84 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 30 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 45.4% yield of d-(3E, 16S)-16-methyl-15-epi-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (376 mg, 0.949 mmoles) as a less polar eluate, followed by 40.6% yield of d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (336 mg, 0.848 mmoles) as a more polar eluate. The structure was confirmed by the following data: d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+292.70 (c 0.466, Me OH) IR (liquid film): 3384, 2956, 2922, 1705, 1632, 1448, 1323, 1278, 1249, 1207, 1176, 1075, 1036, 990, 866, 756 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.00 (3H, d, J=6.8Hz), 1.7-1.85 (1H, m), 1.80 (3H ,t, J=2.7Hz), 2.02 (1H, ddd, J=5.2, 8.8, 13.7Hz), 2.15-2.3 (2H, m), 2.35-2.5 (2H, m), 2.55-2.6(1H, m), 2.71 (1H, ddd, J=6.4, 7.3, 8.8Hz), 3.45 (1H, t, J=8.8Hz), 3.80 (3H, s), 3.9-4.0 (1H, m), 4.05-4.1 (1H, m), 5.23 (1H, ddd, J=5.2, 7.3, 8.8Hz), 5.60 (1H, dd, J=7.1, 15.4Hz), 5.69 (1H, dd, J=8.1, 15.4Hz), 6.71 (1H, d, J=15.9Hz), 6.84 (1H, t, J=7.4Hz), 7.08 (1H, d, J=7.4Hz), 7.28 (1H, d, J=7.4Hz), 7.68(1H, d, J=15.9Hz). MASS (EI, m/e):396 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₈O₅, M⁺) : 396.1937 Found (M⁺) : 396.1952 d-(3E, 16S)-16-methyl-15-epi-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 134-135°C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+233.72 (c 0.430, Me OH) IR (K Br) : 3532, 3322, 3244, 2970, 2902, 1711, 1634, 1448, 1346, 1315, 1278, 1253, 1203, 1185, 1168, 1096, 1035, 1017, 978, 949, 864, 748 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.01 (3H, d, J=6.8Hz), 1.75 (1H, d, J=4.9Hz), 1.80 (3H, t, J=2.4Hz), 1.77-1.85 (1H, m), 1.95 (1H, d, J=4.9Hz), 2.06 (1H, ddd, J=4.9, 8.8, 13.7Hz), 2.1-2.3 (2H, m), 2.50 (1H, q, J=8.3Hz), 2.70 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.50 (1H, t, J=8.3Hz), 3.80 (3H, s), 3.95-4.05 (1H, m), 4.25-4.35 (1H, m), 5.25(1H, ddd, J=4.9, 7.3, 8.3Hz), 5.67 (1H, dd, J=5.1, 16.1Hz), 5.74 (1H, dd, J=8.3, 16.1Hz), 6.72 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.6Hz), 7.14 (1H, d, J=7.6Hz), 7.24 (1H, d, J=7.6Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):396 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₈O₅, M⁺) : 396.1937 Found (M⁺) : 396.1959 Example 49 d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ (63) To a solution of d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (221 mg, 0.558 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml 5.0 mmoles) and stirred at room temperature for 40 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, R P-8, Me OH/H₂O) to afford 47.8% yield of d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ (102 mg, 0.267 mmoles). The structure was confirmed by the following data: [α] 25 / D:+276.79 (c 0.556, Me OH) IR (liquid film) : 3384, 2956, 2922, 1705, 1632, 1448, 1323, 1278, 1249, 1207, 1176, 1075, 1036, 990, 866, 756 cm⁻¹ NMR (500MHz, CDCl₃, δ) :0.98 (3H, d, J=6.7Hz), 1.7-1.85 (4H, m), 1.95-2.05 (1H, m), 2.2-2.3 (2H, m), 2.35-2.45 (1H, m), 2.65-2.8 (1H, m), 3.35-3.45 (1H, m), 3.85-4.05 (2H, m), 5.15-5.25 (1H, m), 5.55-5.7 (2H, m), 6.70 (1H, d, J=15.9Hz), 6.8-6.9 (1H, m), 7.05-7.15 (1H, m), 7.2-7.25 (1H, m), 7.73 (1H, d, J=15.9Hz). MASS (EI, m/e):382(M⁺) High resolution mass spectrum Calcd. (C₂₃H₂₆O₅, M⁺) : 382.1780 Found (M⁺) : 382.1800 Example 50 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (64) and 15-epimer thereof (65) To a solution of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (770 mg, 1.71 mmoles) in methanol (35 ml) was added cerous trichloride heptahydrate (1.28 g, 3.42 mmoles), to which sodium borohydride (65.0 mg, 1.71 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. The residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.085 ml, 0.44 mmoles) was added and stirred at room temperature for 8 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 1/1) to afford 43.7% yield of d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (306 mg, 0.746 mmoles) as a less polar eluate, followed by 45.1% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (316 mg, 0.771 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 65.0-68, °C (recrystallized from ethyl acetate/n-hexane) [α] 25 / D:+284.98 (c 0.666, Me OH) IR (K Br) : 3378, 2964, 2922, 2370, 2334, 1715, 1632, 1605, 1593, 1448, 1323, 1276, 1251, 1207, 1176, 1073, 1036, 990, 866, 801, 779, 748, 717, 605, 563 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.97 (3H, s), 0.98 (3H, s), 1.81 (3H, t, J=2.9Hz), 2.00-2.05 (1H, m), 2.08 (1H, dq, J=2.9, 16.1Hz), 2.22 (1H, dq, J=2.9, 16.1Hz), 2.40-2.50 (1H, m), 2.71 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.47 (1H, t, J=8.3Hz), 3.80 (3H, s), 3.90-4.00 (1H, m), 4.00-4.05 (1H, m), 5.23 (1H, ddd, J=5.4, 7.3, 8.8Hz), 5.65-5.75 (2H, m), 6.71 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.3Hz), 7.10 (1H, d, J=7.3Hz), 7.24 (1H, d, J=7.3Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):410 (M⁺) d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester IR (liquid film) : 3422, 2932, 1694, 1632, 1607, 1593, 1448, 1377, 1323, 1249, 1178, 1044, 986, 866, 783, 748, 719 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.98 (6H, s), 1.80 (3H, t, J=3.0Hz), 2.05-2.10 (1H, m), 2.23 (1H, dq, J=2.5, 16.5Hz), 2.45-2.55 (1H, m), 2.69 (1H, dt, J=7.3, 14.0Hz), 3.51 (1H, t, J=8.5Hz), 3.80 (3H, s), 3.99 (1H, dt, J=5.5, 8.5Hz), 4.06 (1H, d, J=3.0Hz), 5.26 (1H, ddd, J=4.9, 7.3, 9.2Hz), 5.70-5.80 (2H, m), 6.71 (1H, d, J=15.9Hz), 6.86 (1H, t, J=7.9Hz), 7.14 (1H, d, J=7.3Hz), 7.24 (1H, d, J=7.9Hz), 7.68 (1H, d, J=15.9Hz). MASS (EI, m/e):410 (M⁺) Example 51 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ (66) To a solution of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (200 mg, 0.488 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (3.9 ml, 3.9 mmoles) and stirred at room temperature for 18 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 95.7% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-3, 4, 18, 18;19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ (185 mg, 0.467 mmoles) as a crude crystal. The structure was confirmed by the following data : [α] 25 / D:+228.57 (c 0.728, Me OH) IR (K Br) : 3700-2500, 2970, 2366, 1688, 1630, 1450, 1251, 1210, 1075, 1036, 990, 866, 781, 748, 669, 609, 542, 443 cm⁻¹ NMR (400MHz, DMSO-d₆, δ) :0.88 (3H, s), 0.89 (3H, s), 1.75-1.8 (1H, m), 1.76 (3H, t, J=2.4Hz), 2.05 (1H, dq, J=2.4, 16.5Hz), 2.12 (1H, dq, J=2.4, 16.5Hz), 2.25 (1H, q, J=7.9Hz), 2.50-2.60 (1H, m), 3.50 (1H, t, J=8.6Hz), 3.75-3.80 (2H, m), 5.20-5.30 (1H, m), 5.54 (1H, dd, J=7.3, 15.9Hz), 5.66 (1H, dd, J=7.3, 15.3Hz), 6.58 (1H, d, J=16.5Hz), 6.86 (1H, t, J=7.3Hz), 7.13 (1H, d, J=7.3Hz), 7.38 (1H, d, J=7.3Hz), 7.55 (1H, d, J=16.5Hz). MASS (EI, m/e):396 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₈O₅, M⁺) : 396.1937 Found (M⁺) : 396.1948 Example 52 d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (67) and 15-epimer thereof (68) To a solution of d-(3E)-15-oxo-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (756 mg, 1.77 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.32 g, 3.54 mmoles), to which sodium borohydride (67.0 mg, 1.77 mmoles) was added aftercooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (3 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.10 ml, 0.53 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (40 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 45.3% yield of d-(3E)-15-epi-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (311 mg, 0.802 mmoles) as a less polar eluate, followed by 39.9% yield of d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (274 mg 0.706 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+248.62 (c 0.582, Me OH) IR (liquid film) : 3400, 2950, 2870, 1710, 1630, 1600, 1590, 1440, 1370, 1320, 1240, 1200, 1170, 1100, 1070, 1040, 980, 890, 860, 800, 780, 750, 720 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.94 (3H, t, J=7.6Hz), 1.55-1.7 (2H, m), 2.04 (1H, ddd, J=5.1, 8.8, 13.9Hz), 2.15-2.3 (1H, m), 2.46 (1H, q, J=8.1Hz), 2.65-2.8 (2H, m), 3.34 (1H, dd, J=8.1, 9.3Hz), 3.4-3.55 (4H, m), 3.80 (3H, s), 3.9-4.05 (1H, m), 4.3-4.4 (1H, m), 5.2-5.3 (1H, m), 5.60 (1H, dd, J=6.1, 15.4Hz), 5.81 (1H, dd, J=8.1, 15.4Hz), 6.71 (1H, d, J=16.1Hz), 6.84 (1H, t, J=7.3Hz), 7.11 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):388 (M⁺) High resolution mass spectrum Calcd. (C₂₂H₂₈O₆, M⁺) : 388.1886 Found (M⁺) : 388.1884 d-(3E)-15-epi-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+242.61 (c 0.528, Me OH) IR (liquid film) : 3420, 2950, 2870, 1700, 1630, 1600, 1590, 1440, 1370, 1320, 1240, 1200, 1170, 1100, 1040, 980, 860, 800, 780, 750, 720 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.95 (3H, t, J=7.3Hz), 1.55-1.7 (2H, m), 1.8-1.9 (1H, m), 2.06 (1H, ddd, J=4.9, 8.8, 13.7Hz), 2.49 (1H, q, J=8.1Hz), 2.55-2.65 (1H, m), 2.68 (1H, ddd, J=6.4, 7.3, 13.7Hz), 3.33 (1H, dd, J=8.1, 9.5Hz), 3.4-3.55 (4H, m), 3.80 (3H, s), 3.95-4.05 (1H, m), 4.3-4.4 (1H, m) 5.2-5.3 (1H, m), 5.63 (1H, dd, J=5.6, 15.5Hz), 5.82 (1H, dd, J=8.1, 15.5Hz), 6.71 (1H, d, J=16.1Hz), 6.84 (1H, t, J=7.3Hz), 7.14 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):388 (M⁺) High resolution mass spectrum Calcd. (C₂₂H₂₈O₆, M⁺) : 388.1886 Found (M⁺) : 388.1882 Example 53 d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (69) To a solution of d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (225 mg, 0.580 mmoles) in methanol (15 ml) was added 1.0 N aqueous sodium hydroxide solution (6.0 ml, 6.0 mmoles) and stirred at room temperature for 20 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (6.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 201 mg of crude crystalline product. The resulting crude crystalline product was recrystallized from ethyl acetate/n-hexane to afford 63.1% yield of d-(3E)-2, 5, 6, 7-tetranor-17-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (137 mg, 0.366 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 154-155°C [α] 25 / D:+271.14 (c 0.402, Me OH) IR (K Br) : 3350, 2960, 2930, 2870, 1700, 1630, 1600, 1590, 1450, 1360, 1290, 1210, 1200, 1110, 1070, 980, 860, 780, 740, 620, 560 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-D₆, δ) :0.94 (3H, t, J=7.2Hz), 1.6-1.7 (2H, m), 2.02 (1H, ddd, J=5.1, 9.0, 13.9Hz), 2.43 (1H, q, J=8.3Hz), 2.67 (1H, dt, J=6.8, 13.9Hz), 3.35-3.55 (5H, m), 3.9-4.0 (1H, m), 4.3-4.4 (1H, m), 5.2-5.3 (1H, m), 5.62 (1H, dd, J=6.4, 15.6Hz), 5.79 (1H, dd, J=8.3, 15.6Hz), 6.69 (1H, d, J=15.9Hz), 6.82 (1H, t, J=7.3 Hz), 7.11 (1H, d, J=7.3Hz), 7.22 (1H, d, J = 7.3Hz), 7.68 (1H, d, J=15.9Hz). MASS (EI, m/e):374 (M⁺) High resolution mass spectrum Calcd. (C₂₁H₂₆O₆, M⁺) : 374.1729 Found (M⁺) : 374.1709 Example 54 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (70) and 15-epimer thereof (71) To a solution of d-(3E)-16, 16-dimethyl-15-oxo-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (945 mg, 2.07 mmoles) in methanol (25 ml) was added cerous trichloride heptahydrate (1.54 g, 4.14 mmoles), to which sodium borohydride (78.3 mg, 2.07 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.16 ml, 0.83 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 42.0% yield of d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (362 mg, 0.870 mmoles) as a less polar eluate, followed by 41.6% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (358 mg 0.861 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+263.88 (c 0.760, Me OH) IR (liquid film) : 3380, 2950, 2860, 1700, 1630, 1600, 1440, 1320, 1270, 1240, 1200, 1160, 1100, 1030, 980, 860, 780, 740, 720 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.92 (3H, s), 0.94 (3H, s), 1.20 (3H, t, J=7.1Hz), 2.0-2.1 (1H, m), 2.4-2.5 (1H, m), 2.70 (1H, dt, J=6.8, 13.7Hz), 3.29 (1H, d, J=9.0Hz), 3.37 (1H, d, J=9.0Hz), 3.4-3.55 (3H, m), 3.80 (3H, s), 3.9-4.0 (2H, m), 5.2-5.3 (1H, m), 5.6-5.7 (2H, m), 6.72 (1H, d, J=15.9Hz), 6.84 (1H, t, J=7.6Hz), 7.08 (1H, d, J=7.6Hz), 7.23 (1H, d, J=7.6Hz), 7.68 (1H, d, J=15.9Hz). MASS (EI, m/e):416 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂O₆, M⁺) : 416.2199 Found (M⁺) : 416.2197 d-(3E)-16, 16-dimethyl-15-epi-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester [α] 25 / D:+220.00 (c 1.090, Me OH) IR (liquid film) : 3400, 2950, 2860, 1700, 1630, 1600, 1440, 1320, 1260, 1240, 1200, 1160, 1100, 1030, 980, 860, 780, 740, 710 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.92 (3H, s), 0.94 (3H, s), 1.22 (3H, t, J=6.8Hz), 2.0-2.1 (1H, m), 2.45-2.55 (1H, m), 2.68 (1H, dt, J=6.8, 14.0Hz), 3.31 (1H, d, J=9.0Hz), 3.37 (1H, d, J=9.0Hz), 3.45-3.55 (3H, m), 3.80 (3H, s), 3.9-4.05 (2H, m), 5.2-5.3 (1H, m), 5.65-5.75 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.6Hz), 7.16 (1H, d, J=7.6Hz), 7.24 (1H, d, J=7.6Hz), 7.68 (1H, d, J=16.1Hz). MASS (EI, m/e):416 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₃₂O₆, M⁺) : 416.2199 Found (M⁺) : 416.2198 Example 55 d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (72) To a solution of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (340 mg, 0.817 mmoles) in methanol (25 ml) was added 1.0 N aqueous sodium hydroxide solution (7.0 ml, 7.0 mmoles) and stirred at room temperature for 20 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (7.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 322 mg of crude crystalline product. The resulting crude crystalline product was recrystallized from ethyl acetate/n-hexane toafford 65.7% yield of d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (215 mg, 0.537 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 130-131°C [α] 25 / D:+273.02 (c 0.482, Me OH) IR (K Br) : 3400, 2970, 2870, 1690, 1630, 1600, 1590, 1440, 1420, 1360, 1320, 1280, 1240, 1220, 1200, 1100, 1040, 980, 870, 800, 780, 740, 620, 560 cm⁻¹ NMR (400MHz, CDCl₃, δ) :0.92 (3H, s), 0.95 (3H, s), 1.21 (3H, t, J=6.8Hz), 2.06 (1H, ddd, J=5.4, 8.8, 13.9Hz), 2.45-2.55 (1H, m), 2.69 (1H, dt, J=6.8, 13.9Hz), 3.30 (1H, d, J=9.0Hz), 3.37 (1H, d, J=9.0Hz), 3.45-3.55 (3H, m), 3.9-4.0 (2H, m), 5.2-5.3 (1H, m), 5.65-5.75 (2H, m), 6.72 (1H, d, J=16.1Hz), 6.85 (1H, t, J=7.2Hz), 7.12 (1H, d, J=7.2Hz), 7.25 (1H, d, J=7.2Hz), 7.76 (1H, d, J=16.1Hz). MASS (EI, m/e):402 (M⁺) High resolution mass spectrum Calcd. (C₂₃H₃₀O₆, M⁺) : 402.2042 Found (M⁺) : 402.2014 Example 56 d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (73) and 15-epimer thereof (74) To a solution of d-(3E)-15-oxo-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11 acetate (739 mg, 1.60 mmoles) in methanol (25 ml) was added cerous trichloride heptahydrate (1.19g, 3.20 mmoles), to which sodium borohydride (60.5 mg, 1.60 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 20 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (50 ml), filtered, and the precipitate was washed with ethyl acetate (10 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.12 ml, 0.64 mmoles) was added and stirred at room temperature for 3 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 48.8% yield of d-(3E)-16-phenoxy-15-epi-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (329 mg, 0.780 mmoles) as a less polar eluate, followed by 40.1% yield of d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (271 mg 0.642 mmoles) as a more polar eluate. The structure was confirmed by the following data : d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 105-106°C (recrystallized from Me OH) [α] 25 / D:+276.27 (c 0.704, Me OH) IR (K Br) : 3430, 2950, 2930, 2900, 1720, 1630, 1590, 1500, 1440, 1370, 1260, 1240, 1230, 1190, 1090, 1040, 990, 960, 950, 900, 870, 820, 800, 780, 750, 720, 700, 620 cm⁻¹ NMR (400MHz, CDCl₃, δ) :2.06 (1H, ddd, J=5.2, 8.9, 13.7Hz), 2.15-2.2 (1H, m), 2.50 (1H, q, J=8.5Hz), 2.65-2.75 (2H, m), 3.49 (1H, t, J=8.5Hz), 3.91 (3H, s), 3.93 (1H, dd, J=7.6, 9.4Hz), 3.95-4.05 (1H, m), 4.04 (1H, dd, J=3.8, 9.4Hz), 4.55-4.65 (1H, m), 5.24 (1H, ddd, J=5.2, 7.3, 8.5Hz), 5.72 (1H, dd, J=6.1, 15.6Hz), 5.89 (1H, ddd, J=1.1, 8.5, 15.6Hz), 6.71 (1H, d, J=15.9Hz), 6.83 (1H, t, J=7.3Hz), 6.9-7.05 (3H, m), 7.11 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.25-7.35 (2H, m), 7.68 (1H, d, J=15.9Hz). MASS (EI, m/e):422 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₂₆O₆, M⁺) : 422.1729 Found (M⁺) : 422.1728 d-(3E)-16-phenoxy-15-epi-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester m.p. 111-112°C (recrystallized from ethyl acetate/cyclohexane) [α] 25 / D:+263.19 (c 0.614, Me OH) IR (K Br) : 3500, 2930, 2900, 1690, 1630, 1600, 1590, 1500, 1440, 1380, 1350, 1320, 1290, 1250, 1210, 1200, 1170, 1150, 1130, 1090, 1080, 1050, 1040, 1010, 990, 940, 880, 860, 840, 820, 800, 780, 750, 740, 700, 620, 560, 520 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.75-1.85 (1H, m), 2.07 (1H, ddd, J=5.1, 8.2, 13.9Hz), 2.5-2.6 (2H, m), 2.69 (1H, ddd, J=6.1, 7.2, 13.9Hz), 3.52 (1H, t, J=8.6Hz), 3.80 (3H, s), 3.92 (1H, dd, J=7.3, 9.5Hz), 3.95-4.05 (1H, m), 4.06 (1H, dd, J=3.7, 9.5Hz), 4.55-4.65 (1H, m), 5.26 (1H, ddd, J=5.1, 7.2, 8.6Hz), 5.74 (1H, dd, J=5.5, 15.5Hz), 5.91 (1H, ddd, J=1.2, 8.2, 15.5Hz), 6.71 (1H, d, J=16.2Hz), 6.83 (1H, t, J=7.4Hz), 6.9-7.05 (3H, m), 7.15 (1H, d, J=7.4Hz), 7.23 (1H, d, J=7.4Hz), 7.3-7.4 (2H, m), 7.68 (1H, d, J=16.2Hz). MASS (EI, m/e):422 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₂₆O₆, M⁺) : 422.1729 Found (M⁺) : 422.1707 Example 57 d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (75) To a solution of d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (180 mg, 0.427 mmoles) in methanol (15 ml) was added 1.0 N aqueous sodium hydroxide solution (3.41 ml, 3.41 mmoles) and stirred at room temperature for 30 hours. The reaction mixture was concentrated. To the residue was added water (10 ml), then neutralized with 1.0 N hydrochloric acid (3.41 ml), and extracted with ethyl acetate (60 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 203 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate to afford 67.7% yield of d-(3E)-16-phenoxy-2, 5, 6, 7, 17, 18, 19, 20-octanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (118 mg, 0.289 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 191-192°C [α] 25 / D:+273.37 (c 0.462, Me OH) IR (K Br) :3320, 3430, 3030, 2950, 1690, 1630, 1600, 1590, 1500, 1440, 1410, 1380, 1340, 1280, 1240, 1220, 1130, 1080, 1040, 1020, 990, 970, 940, 900, 860, 810, 780, 750, 740, 700, 620, 600, 570, 520 cm⁻¹ NMR (400MHz, CDCl₃ +DMSO-d₆, δ) :1.99 (1H, ddd, J=5.5, 9.5, 13.6Hz), 2.41 (1H, q, J=8.6Hz), 2.69 (1H, dt, J=6.7, 13.6Hz), 3.44 (1H, t, J=8.6Hz), 3.9-4.05 (3H, m), 4.5-4.6 (1H, m), 5.15-5.25 (1H, m), 5.73 (1H, dd, J=6.7, 15.6Hz), 5.86 (1H, dd, J=8.6, 15.6Hz), 6.67 (1H, d, J=16.0Hz), 6.79 (1H, t, J=7.3Hz), 6.9-7.0 (3H, m), 7.10 (1H, d, J=7.3Hz), 7.21 (1H, d, J=7.3Hz), 7.25-7.35 (2H, m), 7.65 (1H, d, J=16.0Hz). MASS (EI, m/e):408 (M⁺) High resolution mass spectrum Calcd. (C₂₄H₂₄O₆, M⁺) : 408.1573 Found (M⁺) : 408.1573 Example 58 d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (76) To a solution of d-(3E, 16R)-15-oxo-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester, 11-acetate (770 mg, 1.62 mmoles) in methanol (20 ml) was added cerous trichloride heptahydrate (1.21 g, 3.24 mmoles), to which sodium borohydride (61.3 mg, 1.62 mmoles) was added after cooling to 0°C. The solution stirred at 0°C for 10 minutes, to which saturated aqueous sodium hydrogen carbonate (5 ml) was added and concentrated. To the residue was added ethyl acetate (30 ml), filtered, and the precipitate was washed with ethyl acetate (20 ml×2). The filtrates were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. Then, the resultant oily product was dissolved in dry methanol (20 ml) under argon atomosphere, to which a solution of sodium methoxide in methanol (5.22 N, 0.12 ml, 0.65 mmoles) was added and stirred at room temperature for 2 hours. This reaction mixture was then neutralized with acetic acid and concentrated. To the residue was added water (20 ml) and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated. The resultant residue was purified by Lobar Column (Merck, silica gel : ethyl acetate/cyclohexane = 2/1) to afford 79.0% yield of d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (556 mg, 1.28 mmoles). The structure was confirmed by the following data : [α] 25 / D:+265.13 (c 0.436, Me OH) IR (K Br) : 3340, 2960, 1710, 1630, 1600, 1590, 1490, 1450, 1320, 1270, 1240, 1200, 1170, 1100, 1080, 1060, 990, 970, 950, 920, 860, 800, 780, 750, 720, 700 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.30 (3H, d, J=6.4Hz), 2.04 (1H, ddd, J=5.1, 8.8, 14.0Hz), 2.46 (1H, q, J=8.4Hz), 2.70 (1H, dt, J=6.8, 14.0 Hz), 3.47 (1H, t, J=8.4Hz), 3.80 (3H, s), 3.9-4.0 (1H, m) 4.21 (1H, t, J=6.4Hz), 4.25-4.35 (1H, m), 5.2-5.3 (1H, m), 5.67 (1H, dd, J=6.4, 15,1Hz), 5.84 (1H, dd, J=8.4, 15.1Hz), 6.71 (1H, d, J=16,1Hz), 6.81 (1H, t, J=7.3Hz), 6.9-7.0 (3H, m), 7.06 (1H, d, J=7.3Hz), 7.23 (1H, d, J=7.3Hz), 7.25-7.35 (2H, m), 7.67 (1H, d, J=16.1Hz). MASS (EI, m/e):436 (M⁺) High resolution mass spectrum Calcd. C₂₆H₂₈O₆, M⁺) : 436.1886 Found (M⁺) : 436.1862 Example 59 d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (77) To a solution of d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (270 mg, 0.619 mmoles) in methanol (20 ml) was added 1.0 N aqueous sodium hydroxide solution (5.0 ml, 5.0 mmoles) and stirred at room temperature for 24 hours. The reaction mixture was concentrated. To the residue was added water (15 ml), then neutralized with 1.0 N hydrochloric acid (5.0 ml), and extracted with ethyl acetate (50 ml, 20 ml). The organic layers were combined, washed with water (20 ml) and with brine (20 ml), dried over anhydrous magnesium sulfate, and concentrated to give 267 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate to afford 71.9% yield of d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (188 mg, 0.445 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 150.5-151.5°C [α] 25 / D:+254.22 (c 0.402, Me OH) IR (K Br) :3400, 2970, 1680, 1630, 1600, 1490, 1450, 1420, 1370, 1290, 1240, 1100, 1060, 1040, 980, 970, 940, 860, 800, 780, 750 cm⁻¹ NMR (500 M Hz, CDCl₃ +DMSO-d₆, δ) :1.31 (3H, d, J=6.3Hz), 1.95-2.05 (1H, m), 2.43 (1H, q, J=8.5Hz), 2.68 (1H, dt, J=6.8, 13.7Hz), 3.44 (1H, t, J=8.5Hz), 3.85-3.95 (1H, m), 4.25 (1H, t, J=6.3Hz), 4.3-4.4 (1H, m), 5.15-5.25 (1H, m), 5.70 (1H, dd, J=6.3, 15.4Hz), 5.82 (1H, dd, J=8.5, 15.4Hz), 6.69 (1H, d, J=16.1Hz), 6.79 (1H, t, J=7.3Hz), 6.9-7.0 (3H, m), 7.08 (1H, d, J=7.3Hz), 7.22 (1H, d, J=7.3Hz), 7.25-7.35 (2H, m), 7.66 (1H, d, J=16.1Hz). MASS (EI, m/e):422 (M⁺) High resolution mass spectrum Calcd. (C₂₅H₂₆O₆, M⁺) : 422.1729 Found (M⁺) : 422.1729 Example 60 d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (78) To a solution of diisopropylamine (1.25 ml, 8.89 mmoles) in dry THF under argon at -78°C was added 1.67 N n-butyl lithium/n-hexane solution (5.00 ml, 8.35 mmoles), which was stirred for 20 minutes. To the solution was added d-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-4, 8-inter-m-phenylene PGI₂ methyl ester (1.1 g, 2.43 mmoles), which was stirred at -78°C for 40 minutes. To the reaction mixture were added diphenyl diselenide (1.14 g, 3.65 mmoles) and hexamethylphosphoric triamide (HMPA) (0.85 ml), which was stirred at -78°C for an hours. After the addition of 1 N hydrochloric acid (5 ml) and water (10 ml), the reaction mixture was raised to room temperature. The reaction mixture was extracted with ethyl acetate (30 ml×3) after THF was distilled off. The organic layers were combined, washed with brine (100 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by column chromatography (Art 9385, Merck, ethyl acetate : cyclohexane = 1:1, then 3:2) to afford 1.17 g of white crystalline product. Then, 1.17 g of the white crystalline product was dissolved in 100 ml of diethyl ether, to which 3.5 ml of 35% aqueous hydrogen peroxide was added under cooling with ice and stirred for 20 minutes. To the reaction mixture was added 30 ml of saturated aqueous sodium bisulfite, stirred for 20 minutes, and partitioned. The aqueous layers were extracted twice with 50 ml of ethyl acetate. The organic layers were combined, washed with brine, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by column chromatography (Art 7734, Merck, ethyl acetate/cyclohexane = 1/1) to afford 0.69 g of d-(3E)-16-methyl-16-phenoxy-2,5,6,7,18,19,20-heptanor-3,4-didehydro-4,8-inter-m-phenylene PGI₂ methyl ester (0.69 g, 1.53 mmoles, yield 63.0%). The structure was confirmed by the following data : m.p. 133-134°C (recrystallized from ethyl acetate/cyclohexane) [α] 25 / D:+252.54 (c 0.118, Me OH) IR (K Br) : 3400, 2980, 1700, 1630, 1590, 1495, 1440, 1378, 1365, 1320, 1280, 1240, 1225, 1200, 1170, 1150, 1130, 1095, 1090, 1065, 1030, 980, 975, 880, 870, 790, 740, 700 cm⁻¹ NMR (400 MHz, CDCl₃, δ) : 1.24 (3H, s), 1.26 (3H, s), 2.01-2.09 (1H, m), 2.45-2.51 (1H, m), 2.65-2.80 (2H, m), 3.2 (1H, br.s), 3.45-3.50 (1H, m), 3.79 (3H, s), 3.95-4.05 (1H, m), 4.17-4.23 (1H, m), 5.20-5.25 (1H, m), 5.70-5.81 (2H, m), 6.70-7.30 (9H, m), 7.65-7.72 (1H, m). MASS (EI, m/e):450 (M⁺) Example 61 d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (79) To a solution of d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ methyl ester (690 mg, 153 mmoles) in methanol (40 ml) was added 1.0 N aqueous sodium hydroxide solution (15 ml, 15 mmoles) and allowed to stand at room temperature for 2 days. The reaction mixture was concentrated. To the residue was added water, then neutralized with 1.0 N hydrochloric acid, and extracted with ethyl acetate (50 ml×2). The organic layers were combined, washed with water and with brine, dried over sodium sulfate, and concentrated to give 660 mg of crude crystalline product. The crude crystalline product was recrystallized from ethyl acetate/cyclohexane to afford 72.5% yield of d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ (482 mg, 1.11 mmoles) as a white crystal. The structure was confirmed by the following data : m.p. 99.1∼100°C [α] 25 / D:+245.95 (c 0.420, Me OH) IR (K Br) : 3500, 2970, 1680, 1630, 1590, 1485, 1440, 1220, 1130, 980, 955, 860, 780, 745, 700 cm⁻¹ NMR (400MHz, CDCl₃, δ) :1.25 (3H, s), 1.27 (3H, s), 2.06-2.12 (1H, m), 2.49-2.57 (1H, m), 2.68-2.75 (1H, m), 3.52 (1H, t, J=8.3Hz), 3.98-4.08 (1H, m), 4.22 (1H, d, J=6.8Hz), 5.24-5.30 (1H, m), 5.74 (1H, dd, J=6.8, 15.6Hz), 5.85 (1H, dd, J=8.6, 15.6Hz), 6.73 (1H, d, J=15.9Hz), 6.85 (1H, t, J=7.8Hz), 7.00 (2H, d, J=7.8Hz), 7.11-7.15 (2H, m), 7.25-7.30 (3H, m), 7.76 (1H, d, J=15.9Hz). MASS (EI, m/e):436 (M⁺) High resolution mass spectrum Calcd. (C₂₆H₂₈O₆, M⁺) : 436.1886 Found (M⁺) : 436.1840 Example 62 Gastric Cytoprotection Gastric cytoprotection was measured according to the method of A. Robert, et al. (Gastroenterlogy 77 (3), 443 (1979). Thirty minutes later after the test compound was administered, the animals were given orally 0.2N Na OH and killed one hour later by chloroform anesthesia. The stomach was taken out, fixed with 5% formalin solution, and opened along greater curvature. The length of the lesion brought about in the stomach is measured and expressed in terms of the ulcer index. Gastric cytoprotection activity is expressed in Table 1 below as an ED₅₀ value (dose in µg/Kg which reduces an ulcer index by 50% of that in a control animal (ulcer index : 100%)). The observed values are shown in Table 1 below. Example 63 Gastric Acid Secretion Inhibition Male SD rats were operated by means of ventrotomy under urethane anesthesia. A double cannula was inserted into the fundus of the rat. The stomach lumen was continuously perfused with a physiological saline solution. The perfusate was drawn into the pH meter to continuously measure its pH (M. Ghosh, H. Schild, Br. J. Pharmacol, 13 , 54 (1958)). Pentagastrin was infused continuously at a rate of 0.05 µg/Kg/min. to stimulate gastric acid secretion. The test compounds were injected intravenuously into the femoral vein when the pH reached a steady state at about 4.0. Gastric acid secretion inhibition activity is calculated from the area made by pH augmentation against time. The potency of the compounds is compared and expressed in terms of PGE₂ ratio where PGE₂ is set as 1. The observed values are shown in Table 2 below. Example 64 Inhibiting Effect of Platelet Aggregation Blood collected from human intermediate cubital vein was centrifuged at 800 rpm for 10 minutes. The supernatant was taken out as platelet rich plasma (PRP). Aliquots of PRP were dispensed into test tubes to which adenosine 2-phosphate (ADP) was added (final concentration : 10 µM) to induce platelet aggregation. The extent of platelet aggregation is determined by an aggregometer (Rika Denki, Tokyo) as a change of turbidity. The test compound is added in one minute prior to the addition of ADP. IC₅₀ values are calculated as a concentration of test compound which inhibits platelet aggregation by 50 %. The observed results are shown in Table 3 below.

Claims: Claims for the following Contracting States : DE, GB, FR, IT, NL, SE, LI, CH, BE, AT, LU, DK A 2,5,6,7-tetranor-4,8-inter-m-phenylene PGI₂ derivative having the following formula : wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms , or (3) Ar wherein Ar is as defined above. A PGI₂ derivative according to Claim 1 wherein R₁ is selected from the group consisting of hydrogen, a pharmacologically acceptable cation, and methyl. A PGI₂ derivative according to Claim 1 or 2 wherein R₂ is selected from the group consisting of normal alkyl group having 4 to 8 carbon atoms and branched alkyl group having 3 to 8 carbon atoms. A PGI₂ derivative according to Claim 1 or 2 wherein R₂ is -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. A PGI₂ derivative according to Claim 1 or 2 wherein R₂ is -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl. A PGI₂ derivative according to Claim 1 or 2 wherein R₂ is -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl. A PGI₂ derivative according to Claim 1 or 2 wherein R₂ is -C t H 2t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. d-(3E)-16, 16 dimethyl 2, 5, 6, 7 tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4 didehydro-4, 8-inter-m-phenylene PGI₂. d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂. d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro 4, 8 inter-m-phenylene PGI₂. d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. A process for the preparation of a PGI₂ derivative defined in Claim 1 which comprises converting a compound having the formula (IV) : wherein R is an ester residue and R₂ is as defined above, to compounds (V) and (VI) : wherein R₂ is as defined above. A process as claimed in Claim 16 comprising the steps of (i) oxidising the compound of formula I below to an aldehyde of formula II; (ii) converting said aldehyde of Formula II to an α, β-unsaturated ketone of formula III; (iii) reducing said α, β-unsaturated ketone of formula III to a substituted allyl alcohol of formula IV; and (iv) transesterifying the compound of formula IV with methanol to form compounds of formula V and formula VI. A process as claimed in Claim 17 wherein step (ii) is effected by condensing the compound of formula II with a dimethyl phosphonate having the formula where R₂ is as defined in Claim 1. A process for the preparation of a PGI₂ derivative defined in Claim 1 which comprises converting a compound having the formula (VIII) : wherein R₂ is as defined above, to a compound having the formula (V) : wherein R₂ is as defined above. A process for the preparation of a PGI₂ derivative of formula V below wherein R₂ is as defined in Claim 1, which comprises (i) phenylselenizing the carbon atom alpha to the COOMe group in a compound of formula VII to form a compound of formula VIII, and (ii) dephenylselenizing the compound of formula VIII. A process as claimed in Claim 20 wherein step (ii) comprises reacting the compound of formula VIII with hydrogen peroxide. A process for the preparation of a PGI₂ derivative having the formula IX or X below wherein R₂ is as defined in Claim 1 which comprises hydrolysing a methyl ester of the formula V or VI below, respectively A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is an ester residue and R₂ is as defined in Claim 1, said process comprising esterifying a compound of the formula A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is a pharmacologically acceptable cation and R₂ is as defined in Claim 1, said process comprising converting a carboxylic acid of the formula to the corresponding salt thereof. A process as claimed in any one of Claims 16 to 24, wherein R₂ is selected from normal alkyl groups having from 4 to 8 carbon atoms, branched alkyl groups having from 3 to 8 carbon atoms, -Z- Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl; -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl. -C t H 2t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. A pharmaceutical composition for the treatment of ulcer which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of thrombosis which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of arteriosclerosis which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of cerebral infarction which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of peripheral circulatory disturbance which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of hepatitis which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for the treatment of diabetic neuropathy which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. A pharmaceutical composition for induction of labor which comprises a PGI₂ derivative defined in any one of Claims 1 to 15 as an active ingredient. The use for the manufacture of a pharmaceutical composition of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula: wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue : R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use for the manufacture of a pharmaceutical composition for the inhibition of platelet aggregation, the inhibition of platelet adhesion, the inhibition of gastric acid secretions, the protection of gastric mucosa cell, bronchodilation, vasodilation, luteo-regression or uterotonic control, of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula: wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use for the manufacture of a pharmaceutical composition for any of the following treatments, namely the treatment of ulcers the treatment of thrombosis the treatment of arteriosclerosis the treatment of cerebral infarction the treatment of peripheral circulatory disturbance the treatment of hepatitis the treatment of diabetic neuropathy the induction of labour of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula : wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use of a PGI₂ derivative as claimed in Claim 34, Claim 35 or Claim 36 wherein R₁ is selected from the group consisting of hydrogen, a pharmacologically acceptable cation, and methyl. The use of a PGI₂ derivative as claimed in any one of Claims 34 to 37 wherein R₂ is selected from normal alkyl groups having 4 to 8 carbon atoms, branched alkyl groups having 3 to 8 carbon atoms, -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula: C t H 2t , t is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl; -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl, and -C t H 2t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. A use as claimed in Claim 34, Claim 35 or Claim 36 wherein the PGI₂ derivative is selected from d (3E) 16, 16 dimethyl 2, 5, 6, 7 tetranor- 3, 4-didehydro-4, 8-inter-m-phenylene PGI₂; d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E-)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8 inter-m-phenylene PGI₂ and d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂. Claims for the following Contracting State : ES A process for the preparation of a PGI₂ derivative which comprises converting a compound having the formula (IV) : to compounds (V) and (VI) : wherein R is an ester residue and R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. A process as claimed in Claim 1 comprising the steps of (i) oxidising the compound of formula I below to an aldehyde of formula II; (ii) converting said aldehyde of formula II to an α, β-unsaturated ketone of formula III; (iii) reducing said α, β-unsaturated ketone of formula III to a substituted allyl alcohol of formula IV; and (iv) transesterifying the compound of formula IV with methanol to form compounds of formula V and formula VI. A process as claimed in Claim 2 wherein step (ii) is effected by condensing the compound of formula II with a dimethyl phosphonate having the formula where R₂ is as defined in Claim 1. A process for the preparation of a PGI₂ derivative of formula V below, wherein R₂ is as defined in Claim 1 which comprises converting a compound having the formula (VIII) : wherein R₂ is as defined above, to a compound having the formula (V) : wherein R₂ is as defined above. A process for the preparation of a PGI₂ derivative of formula V below wherein R₂ is as defined in Claim 1, which comprises (i) phenylselenizing the carbon atom alpha to the COOMe group in a compound of formula VII to form a compound of formula VIII, and (ii) dephenylselenizing the compound of formula VIII. A process as claimed in Claim 5 wherein step (ii) comprises reacting the compound of formula VIII with hydrogen peroxide. A process for the preparation of a PGI₂ derivative having the formula IX or X below wherein R₂ is as defined in Claim 1 which comprises hydrolysing a methyl ester of the formula V or VI below, respectively A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is an ester residue and R₂ is as defined in Claim 1, said process comprising esterifying a compound of the formula A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is a pharmacologically acceptable cation and R₂ is as defined in Claim 1, said process comprising converting a carboxylic acid of the formula to the corresponding salt thereof. A process as claimed in any one of Claims 1 to 9, wherein R₂ is selected from normal alkyl groups having from 4 to 8 carbon atoms, branched alkyl groups having from 3 to 8 carbon atoms, -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl; -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl. -C t H 2 t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. Claims for the following Contracting State : GR A process for the preparation of a PGI₂ derivative which comprises converting a compound having the formula (IV) : to compounds (V) and (VI) : wherein R is an ester residue and R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. A process as claimed in Claim 1 comprising the steps of (i) oxidising the compound of formula I below to an aldehyde of formula II; (ii) converting said aldehyde of formula II to an α, β-unsaturated ketone of formula III; (iii) reducing said α, β-unsaturated ketone of formula III to a substituted allyl alcohol of formula IV; and (iv) transesterifying the compound of formula IV with methanol to form compounds of formula V and formula VI. A process as claimed in Claim 2 wherein step (ii) is effected by condensing the compound of formula II with a dimethyl phosphonate having the formula where R₂ is as defined in Claim 1. A process for the preparation of a PGI₂ derivative of formula V below, wherein R₂ is as defined in Claim 1 which comprises converting a compound having the formula (VIII) : wherein R₂ is as defined above, to a compound having the formula (V) : wherein R₂ is as defined above. A process for the preparation of a PGI₂ derivative of formula V below wherein R₂ is as defined in Claim 1, which comprises (i) phenylselenizing the carbon atom alpha to the COOMe group in a compound of formula VII to form a compound of formula VIII, and (ii) dephenylselenizing the compound of formula VIII. A process as claimed in Claim 5 wherein step (ii) comprises reacting the compound of formula VIII with hydrogen peroxide. A process for the preparation of a PGI₂ derivative having the formula IX or X below wherein R₂ is as defined in Claim 1 which comprises hydrolysing a methyl ester of the formula V or VI below, respectively A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is an ester residue and R₂ is as defined in Claim 1, said process comprising esterifying a compound of the formula A process for the preparation of a PGI₂ derivative of the formula wherein R₁ is a pharmacologically acceptable cation and R₂ is as defined in Claim 1, said process comprising converting a carboxylic acid of the formula to the corresponding salt thereof. A process as claimed in any one of Claims 1 to 9, wherein R₂ is selected from normal alkyl groups having from 4 to 8 carbon atoms, branched alkyl groups having from 3 to 8 carbon atoms, -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl; -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl. -C t H 2t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. The use for the manufacture of a pharmaceutical composition of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula: wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use for the manufacture of a pharmaceutical composition for the inhibition of platelet aggregation, the inhibition of platelet adhesion, the inhibition of gastric acid secretions, the protection of gastric mucosa cell, bronchodilation, vasodilation, luteo-regression or uterotonic control of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula: wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above, R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use for the manufacture of a pharmaceutical composition for any of the following treatments, namely the treatment of ulcers the treatment of thrombosis the treatment of arteriosclerosis the treatment of cerebral infarction the treatment of peripheral circulatory disturbance the treatment of hepatitis the treatment of diabetic neuropathy the induction of labour of a 2, 5, 6, 7-tetranor-4, 8-inter-m-phenylene PGI₂ derivative having the following formula : wherein R₁ is hydrogen, a pharmacologically acceptable cation, or an ester residue ; R₂ is (i) normal alkyl group having 1 to 12 carbon atoms or branched alkyl group having 3 to 14 carbon atoms ; (ii) -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula : C t H 2t , t is an integer of 1 to 6, and Ar is phenyl group unsubstituted or substituted by 1 to 4 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy ; (iii) -Z-R₃ wherein Z is as defined above, R₃ is cycloalkyl group having 3 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms ; (iv) -C t H 2t -C≡C-R₄ wherein C t H 2t is as defined above, R₄ is normal alkyl group having 1 to 6 carbon atoms ; (v) -C t H 2t -O-R₅ wherein C t H 2t is as defined above , R₅ is (1) normal alkyl group having 1 to 6 carbon atoms or branched alkyl group having 3 to 6 carbon atoms, (2) cyclopentyl or cyclohexyl group unsubstituted or substituted by 1 to 4 normal alkyl substituents containing 1 to 4 carbon atoms, or (3) Ar wherein Ar is as defined above. The use of a PGI₂ derivative as claimed in Claim 11, Claim 12 or Claim 13 wherein R₁ is selected from the group consisting of hydrogen, a pharmacologically acceptable cation, and methyl. The use of a PGI₂ derivative as claimed in any one of Claims 11 to 14 wherein R₂ is selected from normal alkyl groups having 4 to 8 carbon atoms, branched alkyl groups having 3 to 8 carbon atoms, -Z-Ar wherein Z is a valence bond or normal or branched alkylene group having the formula: C t H 2t , t is an integer of 1 to 4, and Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy; -Z-R₃ wherein Z is a valence bond or normal or branched alkylene having the formula : C t H 2t , t is an integer of 1 to 4, and R₃ is cyclopentyl or cyclohexyl; -C t H 2t -C≡C-R₄ wherein t is an integer of 1 to 4, and R₄ is methyl, ethyl, propyl, or butyl, and -C t H 2t -O-R₅ wherein t is an integer of 1 to 4, and R₅ is (1) methyl, ethyl, propyl, or butyl, (2) cyclopentyl or cyclohexyl or (3) Ar wherein Ar is phenyl group unsubstituted or substituted by 1 or 2 substituents selected from alkyl, methoxy, chloro, bromo, fluoro, iodo, trifluoromethyl, nitro, cyano, phenyl and phenoxy. A use as claimed in Claim 11, Claim 12 or Claim 13 wherein the PGI₂ derivative is selected from d(3E)16, 16 dimethyl 2, 5, 6, 7 tetranor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂; d-(3E)-15-phenyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E)-15-(p-chlorophenyl)-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E)-15-cyclohexyl-2, 5, 6, 7, 16, 17, 18, 19, 20-nonanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E, 16S)-16-methyl-2, 5, 6, 7-tetranor-3, 4, 18, 18, 19, 19-hexadehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E)-16, 16-dimethyl-2, 5, 6, 7-tetranor-18-oxa-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂ ; d-(3E, 16R)-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8 inter-m-phenylene PGI₂ and d-(3E)-16-methyl-16-phenoxy-2, 5, 6, 7, 18, 19, 20-heptanor-3, 4-didehydro-4, 8-inter-m-phenylene PGI₂.

Inventors: ENDOH TAKASHI, HOSHI KAZUHIRO, ITOU SHIGEKI, OHNO KIYOTAKA, OHTAKE ATSUSHI, ENDOH, TAKASHI, HOSHI, KAZUHIRO, ITOU, SHIGEKI, OHNO, KIYOTAKA, OHTAKE, ATSUSHI
Applicants: TORAY INDUSTRIES, TORAY INDUSTRIES, INC.
Application year: 1990
Main classification: C07D307
IPC codes: A61P33, A61P43, C07C405, A61K31, C07D307