9-deoxy-9a-methylene isosteres of pgi.sub.2 and process for their preparation

Abstract From the Canadian patent

The invention relates to new compounds of formula I I, wherein R is (a) a free or esterified carboxy group; (b) -C(OR')3 where, each R' group is independently C1-C6-alkyl or phenyl; (c) -CH2-R" where R", is hydroxy or C2-C7-alkoxy; (d) where Ra and Rb are chosen inde-, pendently from the group hydrogen C1-C6-alkyl, C2-C6-alkanoyl and phenyl; (e) -C?N; (f) , radical; (g) -CHO; or (h) radical, where each X' is independently -O- or -S- and the R'a and R'b groups whether the same or different, are C1-C6-alkyl or together form a straight or branched C2-C6-alkenylene chain; D is: (trans), -C?C-, , -O-, -S-, or , where Rc may be hydrogen, C1-C6-alkyl or C2-C6-alkanoyl; one of R1 and R2 and …