Synthesis and evaluation of 17α-E-20-(heteroaryl)norpregn-1,3,5(10),20 tetraene-3,17β-diols [17α-(heteroaryl)vinyl estradiols] as ligands for the estrogen receptor-α ligand binding domain (ERα-LBD).

Abstract A series of 17α-(heteroaryl)vinyl estradiols was prepared to evaluate the influence of heteroatom on the affinity and efficacy of estrogenic ligands for the estrogen receptor-alpha ligand binding domain (ERα-LBD). The products demonstrated reduced binding affinity compared to the parent 17α-E-phenylvinyl estradiol, but the binding was relatively independent of the heteroatom. The greatest influence of the heteroatom was evident in the efficacy of the compounds as the thienyl derivatives 2f , g were more potent than either the pyridyl 2b – d or pyrimidinyl 2e analogs. The results suggest that a subtle interplay of interactions between the ligands and the receptor influences the biological response.