2-Substituted-16-ene-22-thia-1α,25-dihydroxy-26,27-dimethyl-19-norvitamin D3 analogs: Synthesis, biological evaluation, and crystal structure

2-Substituted-16-ene-22-thia-1α,25-dihydroxy-26,27-dimethyl-19-norvitamin D3 analogs (grey) exhibited an extremely higher level of potency than the natural hormone (green). X-ray crystallography revealed the key interactions between the ligands and the receptor.