4,5-Disubstituted cis-Pyrrolidinones as Inhibitors of 17β-Hydroxysteroid Dehydrogenase II. Part 1. Synthetic Approach.

17β-Hydroxysteroid dehydrogenase II (17β-HSD II) antagonists may provide an important way into preventing the onset of osteoporosis. The discovery of 4,5-disubstituted cis-pyrrolidinones as 17β-HSD II inhibitors led to the development of an efficient intramolecular Michael addition, followed by catalytic hydrogenation to obtain the desired cis configuration.