19,20-Didehydro-PG.sub.2 compounds

A compound of the formula ##STR5## wherein D is (1) cis--CH.dbd.CH--CH.sub.2 --(CH.sub.2).sub.g --CH.sub.2 --,

• (2) cis--CH.dbd.CH--CH.sub.2 --(CH.sub.2).sub.g --CF.sub.2,
• (3) cis--CH.sub.2 --CH.dbd.CH--CH.sub.2 --CH.sub.2 --,
• (4) trans--(CH.sub.2).sub.3 --CH.dbd.CH--,
• wherein g is zero, one, 2, or 3;
• wherein Q is ##STR6## wherein R.sub.5 is hydrogen or methyl, wherein R.sub.6 is (a) hydrogen, (b) alkyl of one to 12 carbon atoms, inclusive, (c) cycloalkyl of 3 to 10 carbon atoms, inclusive, (d) aralkyl of 7 to 12 carbon atoms, inclusive, (e) phenyl, (f) phenyl substituted with one, 2, or 3 chloro or alkyl groups of one to 3 carbon atoms, inclusive;
• ##STR7## wherein R.sub.28 is phenyl, p-bromophenyl, p-biphenylyl, p-nitrophenyl, p-benzamidophenyl, or 2-naphthyl, or
• (o) a pharmacologically acceptable cation;
• wherein R.sub.2 is hydrogen, hydroxyl, or hydroxymethyl;
• wherein R.sub.3 and R.sub.4 are hydrogen, methyl, or fluoro, being the same or different, with the proviso that one of R.sub.3 and R.sub.4 is fluoro only when the other is hydrogen or fluoro;
• wherein W is ##STR8## and wherein X is cis-- or trans--CH.dbd.CH-- or --C.tbd.C--.