| 549 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
|
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {1} |
| * | DD | .~ HETEROCYCLIC CARBON COMPOUNDS CONTAINING A HETERO RING HAVING CHALCOGEN (I.E., OXYGEN, SULFUR, SELENIUM, OR TELLURIUM) OR NITROGEN AS THE ONLY RING HETERO ATOMS (Class 540, subclass 1) {2} |
| 200 | DF | .~.~ Oxygen containing hetero ring (e.g., dioxirane, etc.) {16} |
| 346 | DF | .~.~.~ The hetero ring has at least seven members {2} |
| 347 | DF | .~.~.~.~ Plural ring oxygens in the hetero ring {2} |
| 352 |  | .~.~.~.~.~ Three or more ring oxygens in the hetero ring {1} |
| 353 | DF | .~.~.~.~.~.~> Exactly four oxygens in the hetero ring |