Abstract 21-Acetoxy-16α, 17α-epoxypregn-4-ene-3, 20-dione (1) enters a reaction with acetonitrile catalyzed by perchloric acid, giving unusual products with the furostane skeleton. In contrast to analogous reactions, the reaction with sodium azide results in the azido derivative possessing the non-rearranged ring D. The 1 H NMR, 13 C NMR, and mass spectra are discussed.
