SEARCH Articles Figures Tables Compounds containing Three or Four Fused Heterocyclic Rings (5,5,5), (5,5,6), (5,5,7), (5,6,7), and Electronic spectra of large-ring heterocyclic compounds Electronic spectra of small-ring heterocyclic compounds Fused-Ring Heterocyclic Compounds Heteroaromatic compounds Heterocyclic rings Heterocycles Containing a Ring-Junction Nitrogen (Bridgehead Compounds) Heterocyclic Compounds with Three or More Rings Heterocyclic Oxygen Compounds with Three or More Rings Heterocyclic compounds degenerate ring transformations Heterocyclic compounds five-membered rings Heterocyclic compounds four heteroatomic rings Heterocyclic compounds four-membered ring opening Heterocyclic compounds four-membered ring, formation Heterocyclic compounds four-membered rings Heterocyclic compounds ring opening Heterocyclic compounds ring strain Heterocyclic compounds ring systems Heterocyclic compounds seven-membered ring opening Heterocyclic compounds seven-membered rings Heterocyclic compounds three heteroatomic rings Heterocyclic compounds three-membered ring opening Heterocyclic compounds three-membered rings Imine compounds heterocyclic rings Polymerizability, heterocyclic ring compounds Ring Transformation of Oxiranes into other Heterocyclic Compounds Ring closure heterocyclic compounds Ring compounds heterocyclic five-membered rings Ring compounds heterocyclic five-membered rings from Single-Ring Heterocyclic Sulfur Compounds