STEREOCHEMISTRY OF SUBSTITUTION OF ALLYLI C HYDROXYL WITH FLUORINE INPROSTAGLANDINS - SYNTHESIS OF 15-FLUORO-11,15-DIDEOXYPROSTAGLANDINS E(1)

(+/-)-15-Fluoro-11,15-dideoxyprostaglandin E(1) and its methyl and eth yl esters were synthesized. Dehydroxyfluorination reaction of (+/-)-11 -deoxyprostaglandin E(1) esters with various reagents based on SF4 was studied. Along with the target 15-fluorides (mixtures of alpha- and b eta-epimers), products of allylic shift and dehydration in a ratio dep endent on the fluorination agent were shown to be formed. With a pholi notrifluorosulfuran-tris(morpholine)sulfonium trimethyldifluorosilicat e mixture, the maximal excess (70%) of one of the 15-fluoro epimers wa s achieved. Possible mechanisms of dehydroxyfluorination of(+/-)-11-de oxyprostaglandin E(1) esters with dialkylaminofluorosulfurans were pro posed. Methyl esters of 15-alpha fluoro- and 15-beta fluoro-11,15-dide oxyprostaglandin E(1) exhibited moderate antiaggregation activity in r abbit platelet tests.