Esters of prostacyclin-type compounds

An acid ester of a 6a-carba prostacyclin analog of the formula ##STR2## wherein L.sub.1 is (1) --(CH.sub.2).sub.n -- wherein n is one to 5, inclusive,

• (2) --(CH.sub.2).sub.p -- wherein p is 2, 3, or 4, or
• (3) --(CH.sub.2).sub.v --CH.dbd.CH-- wherein v is 1, 2, or 3,
• wherein M.sub.3 is ##STR3## wherein Q is oxo, .alpha.-H:.beta.-H, .alpha.-OH:.beta.-R.sub.4, or .alpha.-R.sub.4 :.beta.-OH, wherein R.sub.4 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, wherein R.sub.1 alkyl of one to 4 carbon atoms with the proviso that when R.sub.1 is tert-butyl the group ##STR4## is in the 4-position, wherein R.sub.3 is ##STR5## wherein R.sub.5 and R.sub.6 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or fluoro, being the same or different, with the proviso that one of R.sub.5 and R.sub.6 is fluoro only when the other is hydrogen or fluoro;
• and the further proviso that neither R.sub.5 nor R.sub.6 is fluoro when Z is oxa (--O--);
• wherein Z represents an oxa atom (--O--) or C.sub.j H.sub.2j wherein C.sub.j H.sub.2j is a valence bond or alkylene of one to 9 carbon atoms, inclusive, with one to 6 carbon atoms, inclusive between CR.sub.5 R.sub.6 -- and the phenyl ring;
• wherein T is alkyl of one to 4 carbon atoms;
• inclusive, fluoro, chloro, trifluoromethyl, or --OR.sub.7 -- wherein R.sub.7 is alkyl of one to 4 carbon atoms, inclusive and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl and when s is 2 or 3 the T's are either the same or different.
• wherein R.sub.12 is ##STR6## wherein X is (1) trans--CH.dbd.CH--
• (2) cis--CH.dbd.CH--
• (3) --C.tbd.C-- or
• (4) --CH.sub.2 CH.sub.2 --.