Steroidal Silicon Side-Chain Analogues as Potential Antifertility Agents

Article abstract of DOI:10.1021/jm00387a011

A number of silicon-substituted analogues of ethynylestradiol that exhibit modified and enhanced biological activities have been synthesized.Particularly noteworthy are a group of <(trialkylsilyl)ethynyl>estradiol analogues that exhibit high antifertility potency and markedly reduced estrogenic activity.The best compounds synthesized are 17α-<(triethylsilyl)ethynyl>estradiol (5) and 17α-<(tert-butyldimethylsilyl)ethynyl>estradiol (33), which show a separation of antifertility from estrogenic activity in the rat.The results of structure-activity studies indicate a good correlation between the observed biological activities and the calculated van der Waals volumes of the three variable silicon substituents.