16α,17α-Epoxy-5α-hydroxy-6β-nitrooxy-20-oxopregnan-3β-yl acetate

Abstract

The title steroid, C23H33NO8, is a pregnane derivative obtained regio-, stereo- and chemoselectively from the ring opening of the corresponding 5α,6α;16α,17α-diepoxide with bismuth(III) nitrate. There are two symmetry-independent molecules in the asymmetric unit that show no significant differences concerning bond lengths and angles. All rings aretrans-fused. The conformations of the six-membered rings are close to chair forms, while the five-membered ring adopts an envelope conformation. The molecules are held together by an extensive O—H...O hydrogen-bonding network of chains runnning along theaaxis.