A novel isocarbacyclin which is a compound represented by the following formula ##STR1## wherein R.sup.1 represents a hydrogen atom, or a C.sub.1 -C.sub.4 alkyl or alkenyl group; R.sup.2 and R.sup.3 are identical or different and each represents a hydrogen atom, a tri(C.sub.1 -C.sub.7)hydrocarbon-silyl group or a group forming an acetal linkage together with the oxygen atom of the hydroxyl group; R.sup.4 represents a hydrogen atom, a methyl group or a vinyl group; R.sup.5 represents an unsubstituted linear or branched C.sub.3 -C.sub.8 alkyl group which may be interrupted by an oxygen atom, a substituted linear or branched C.sub.1 -C.sub.5 group in which the substituent is a C.sub.1 -C.sub.6 alkoxy group or a phenyl, phenoxy or C.sub.3 -C.sub.10 cycloalkyl group which may be substituted further, a phenyl group which may be substituted, a phenoxy group which may be substituted, or a C.sub.3 -C.sub.10 cycloalkyl group which may be substituted; n is 0 or 1; and Ar represents a substituted or unsubstituted phenyl group, its enantiomorph, or a mixture both in an arbitrary ratio.
                            一种新型异
前列腺素,其化合物由以下式子表示:##STR1## 其中R.sup.1代表氢原子,或C.sub.1-C.sub.4烷基或烯基;R.sup.2和R.sup.3相同或不同,每个代表氢原子,三个(C.sub.1-C.sub.7)烷基基
硅基团或与羟基的氧原子一起形成
缩醛键的基团;R.sup.4代表氢原子,甲基或
乙烯基;R.sup.5代表未取代的线性或支链C.sub.3-C.sub.8烷基,其中可以由氧原子打断,取代的线性或支链C.sub.1-C.sub.5基团,其中取代基为C.sub.1-C.sub.6烷氧基,苯基,苯氧基或C.sub.3-C.sub.10环烷基,可以进一步取代,可以取代的苯基,可以取代的苯氧基,或者可以取代的C.sub.3-C.sub.10环烷基;n为0或1;Ar代表取代或未取代的苯基,其对映体,或两者的混合物,以任意比例。