Oxygen Bonded Directly At The 3-, 11-, And 17-positions Patents (Class 552/569)
- Carbon bonded directly at the 1-, 2- or 4-position (Class 552/571)
- Carbon or halogen bonded directly at the 6- or 7-position (Class 552/572)
- Carbon bonded directly at the 16-position (e.g., betamethasones, dexamethasones, etc.) (Class 552/574)
- Nitrogen or sulfur containing (Class 552/575)
- Unsaturation between the 1- and 2-positions and the 4- and 5-positions (e.g., prednisones, prednisolones, etc.) (Class 552/576)
- Unsaturation between the 4- and 5-positions (e.g., cortisones, etc.) (Class 552/577)
- The cyclopentanohydrophenanthrene ring system is fully saturated (Class 552/579)