Synthesis and Molecular Structure of D-Homo-B-nor-8α Analogs of Steroidal Estrogens

According to the X-ray diffraction and NMR data, two D-homo-B-nor-8α-analogs of steroidal estrogens in crystal and in solution have similar conformations. The distances between hydrogen atoms in their molecules, calculated ab initio and by the PM3 and MM+ methods, correspond to those found experimentally. These results substantiated docking of the modified estrogens into ligand-binding pockets of various estrogen receptor isoforms with a view to search for compounds with improved biological properties. This was demonstrated using 17,17-dimethyl-D-homo-B-nor-8α-estrone as an example.