Stereodivergent Synthesis of 17-α and 17-β-Aryl Steroids: Application and Biological Evaluation of D-Ring Cortistatin Analogues†

One stereocenter makes all the difference: The synthesis and biological evaluation of 17-epi-cortistatin A is reported from a common intermediate used to procure natural cortistatin A. The synthesis features a unique stereocontrolled Raney-Ni reduction process that can be employed to reliably produce both α- and β-configured D-ring aryl steroids. Biological evaluations of these “cortalogs” are reported for the first time.