9 compounds of this family in the library, boiling between 88 and 300 °C. How the family spreads along the axis says something about its shared behaviour. Left of the dashed line are compounds lighter than any essential-oil component — they are gone before the main axis begins. Right of it are compounds heavier than the essential-oil range — they remain after the main axis has run out.
Structure
A carbonyl group in the middle of the chain, with carbon on both sides. It differs from an aldehyde in exactly that detail of position.
Behaviour on a smelling strip
The most varied in behaviour: diacetyl has only four carbons and boils at 88 degrees, alpha-vetivone has fifteen and boils at around 300. The same functional group, two extremes.
Compounds in this family
Ordered by rising boiling point — which is also the order in which you smell them.
| Compound | CAS | Boiling point | Description |
|---|---|---|---|
| Diacetyl | 431-03-8 | 88 °C | Butter, cream, fatty sweetness. At high concentration it turns into an unpleasant artificial-butter note. |
| 3-Octanone | 106-68-3 | 167 °C | Mushroom, slightly fatty, with a faint earthy note. At low concentration it smells like a forest after rain; higher up it smells like a fridge that needs cleaning. |
| 1-Octen-3-one | 4312-99-6 | 175 °C | Metallic, fishy, close to blood. Very strong at extremely low concentration. |
| Fenchone | 1195-79-5 | 193 °C | Camphor, slightly sweet, with a faint anise note. Sharper than true camphor and less dusty. |
| Camphor | 76-22-2 | 204 °C | Dry, sharp, woody, dusty. Heavy and closed; it does not open out like cineole. |
| Carvone | 99-49-0 | 231 °C | Depending on the isomer it is two unrelated smells: the R form gives spearmint, the S form caraway and dill seed. |
| cis-Jasmone | 488-10-8 | 248 °C | Warm jasmine, with a hint of celery and a fatty note. This is the part that makes jasmine sound alive rather than merely sweet. |
| Nootkatone | 4674-50-4 | 290 °C | Grapefruit peel in concentrated form, bitter and warm. Very lasting, hardly evaporating. |
| α-Vetivone | 15764-04-2 | 300 °C | Roots, earth, damp wood. So heavy it almost stands still on a smelling strip. |
Two ways of ordering, two questions
Boiling point answers the question when do you smell this compound. It is the axis this site uses by default, because it maps directly onto what happens on a smelling strip.
Chemical family answers the question how does this compound behave: stable or fragile, soft or sharp, and how you recognise it on an analysis. Trade literature usually presents compound tables along this axis.
Neither axis is more correct than the other. Knowing both means you can read both kinds of document. Read about the boiling-point axis