Antifertility agents. 8. seco steroids. 2. 5,6-secoestradiol and some related compounds

The synthesis and biological evaluation of 3 of the 4 possible isomers of 2-ethyl-3-(p-hydroxyphenyl)-6beta-methyl-trans-bicyclo (4.3.0.) nonan-7beta-ols ring B secoestradiols are reported. Antiimplantation activity of the compounds was studied in female albino rats mated to coeval males of proven fertility. The compounds were administered orally on Days 1-7 postcoitum. Estrogenic activity was evaluated by the immature ovariectomized rat uterine weight and vaginal cornification period. The results show that some of the compounds have marked antiimplantation and estrogenic activity.