SEARCH Articles Figures Tables Heterocyclic 5- membered ring Heterocyclic synthesis six-membered rings Heterocyclics six-membered Nitrogen heterocycles six-membered rings Other Aromatic Six-Membered Ring Heterocyclics Ring Expansion into Six-Membered Heterocycles Rings six-member Selenophens Fused to Six-membered Heterocyclic Aromatic Rings Six-Membered Heterocycled Six-Membered Heterocycles Fused to One Benzene Ring Six-membered aromatic heterocycles can have oxygen in the ring Six-membered heterocycles Six-membered heterocyclic rings Six-membered heterocyclic rings Six-membered ring heterocycles containing one oxygen atom Six-membered ring heterocycles with one