Synthesis and antifertility activity of 3,9-dihydroxy-5,6,6a alpha,6b beta,11,12,12a beta,12b alpha-octahydrodibenzo[a,g]biphenylene, a structural relative of diethylstilbestrol.

The title diphenol, 1a, was synthesized from p,p'-dihydroxy-alpha-truxillic acid and shown to be active as an oral postcoital antifertility agent in rats: ED100 = 100 (micrograms/kg)/day. The oral uterotropic potency was estimated to be 16% of that of diethylstilbestrol (95% confidence limits of potency 8--35%). The structure of the diphenol, 1a, was confirmed by single-crystal X-ray analysis of the dimethyl ether.