| 552 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
|
| * | DD | ORGANIC COMPOUNDS (Class 532, subclass 1) {11} |
| 502 | DF | .~ Cyclopentanohydrophenanthrene ring system containing {21} |
| 623 | DF | .~.~ Two oxygens bonded directly to the cyclopentanohydrophenanthrene ring system {5} |
| 642 |  | .~.~.~ Carbon bonded directly at the 13-position (e.g., 19-norandrostenes, estradienes, etc.) {4} |
| 643 | DF | .~.~.~.~> Carbon or halogen bonded directly at the 1-, 2-, 4- or 5-position |
| 644 | DF | .~.~.~.~> Unsaturation between the 5- and 10-positions {1} |
| 646 | DF | .~.~.~.~> Unsaturation between the 4- and 5-positions (e.g., 19-nortestosterones, 13 beta-alkyl-4-gonene-3,17-diones etc.) {2} |
| 649 | DF | .~.~.~.~> The cyclopentanohydrophenanthrene ring system is fully saturated (e.g., 17 alpha-alkyl-17 beta-hydroxyestran-3-ones, etc.) |