| 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} |
| 356 | DF | .~.~.~ The hetero ring is six-membered {9} |
| 381 | DF | .~.~.~.~ Polycyclo ring system having the hetero ring as one of the cyclos {4} |
| 385 | DF | .~.~.~.~.~ Tricyclo ring system having the hetero ring as one of the cyclos {4} |
| 388 | DF | .~.~.~.~.~.~ The tricyclo ring system consists of three six-membered cyclos (e.g., xanthene, etc.) {4} |
| 390 | DF | .~.~.~.~.~.~.~ Dibenzo(b,d)pyrans (including hydrogenated) {1} |
| 391 |  | .~.~.~.~.~.~.~.~ Plural chalcogens bonded directly to the tricyclo ring system |