95057 ⎘
Heterocyclic compounds containing six-membered rings having one oxygen atom as the only hetero atom, condensed with other rings ortho- or peri-condensed with carbocyclic rings or ring systems; Benzo[b]pyrans, not hydrogenated in the carbocyclic ring with oxygen or sulfur atoms in positions 2 and 4 with one hydrogen atom in position 3
Sub-classes: