7-Membered Rings
With 7-membered rings, the heteroatom must be able to provide an empty pi orbital (e.g., boron) for "normal" aromatic stabilization to be available; otherwise, homoaromaticity may be possible. Compounds with one heteroatom include:
| Heteroatom | Saturated | Unsaturated |
|---|---|---|
| Nitrogen | Azepane | Azepine |
| Oxygen | Oxepane | Oxepine |
| Sulfur | Thiepane | Thiepine |
Those with two heteroatoms include:
| Heteroatom | Saturated | Unsaturated |
|---|---|---|
| Nitrogen | Homopiperazine | Diazepine |
| Nitrogen/sulfur | Thiazepine |
Read more about this topic: Heterocyclic Compound
Famous quotes containing the word rings:
“‘She has got rings on every finger,
Round one of them she have got three.
She have gold enough around her middle
To buy Northumberland that belongs to thee.”
—Unknown. Young Beichan (l. 61–64)