Synthetic and Enzymatic Studies with Potential Alternate Substrates for Human Placental Aromatase: 10β-Trifluoroacetyl and 10β-allyl Steroids

The l0β-trifiuoroacetyl and 10β-allyl analogs, 6 and 13, respectively, of androstenedione have been studied as potential alternate substrates for aromatase. The hitherto undescribed compound 6 was synthesized via the action of trifluoromethyltrimethylsilane on a 19-oxo steroid. There was no conversion of 6 to estrogen by aromatase, although 6 was a competitive inhibitor. Furthermore 13 was not epoxidized significantly by the enzyme, leaving open the mechanism of suicide inactivation of aromatase by the propargylic steroid 10.