A stereoselective total synthesis of 11-oxoprogesterone, a precursor to the corticosteroids, via an intramolecular cycloaddition reaction

Abstract

A Stereoselective synthesis of 11-oxoprogesterone (pregn-4-ene-3,11,20-trione)(21) has been achieved via 19-norpregna-4,9(10)-diene-3,20-dione (14) and pregna-4,9(10)-diene-3,20-dione (18). The compound (14) was derived from the des-A,B-aromatic steroid (6), which was, in turn, constructed in a stereoselective manner via(3) by the thermolysis of the olefinic benzocyclobutene (2).