Dehydration and epimerization of 7-thiaprostaglandin E1 analogues

The kinetics of epimerization and dehydration of 7-thiaprostaglandin E1 (7-S-PGE1) analogues in various solvent systems were examined using HPLC. The epimerization at the C-8 position was rapid and resulted in a considerable amount of the 8-epimer (14-35%) at equilibrium. The dehydration was also rapid compared with that of the natural prostaglandin E1 (PGE1). The lability may be attributed to an effect of the sulfur atom substituted for the C-7 methylene.