3,17.beta.-dihydroxy-20,21-epoxy-19-norpregna-1,3,5(10)-trienes. Synthesis, rearrangement, cytotoxicity, and estrogen-receptor binding

Abstract
Diastereoisomers of 3,17.beta.-dihydroxy-20,21-epoxy-19-norpregna-1,3,5(10)-triene have been prepared as potential antitumor agents. Both isomers undergo the base-catalyzed Payne rearrangement. The isomers were cytotoxic to mammalian cells in culture and were able to displace [3H]estradiol from binding sites in rat uterine cytosols with 1/7 and 1/70 the potency of estradiol. The reasons for this difference are discussed.