Compounds · Sesquiterpenes · Terpenoid pathway
α-Farnesene
Green apple, light wood, slightly sweet. Feels lighter than the ring sesquiterpenes.
- CAS
- 502-61-4
- Formula
- C15H24
- Molar mass
- 204.36
- Odour threshold
- —
- Boiling point
- ≈ 270 °C estimated
Where it comes from
Biosynthetic pathway: Terpenoid pathway — plants build them from identical five-carbon blocks.
Why it sits where it does
Entirely open-chain, with no ring. It boils at about 270 degrees, some five degrees below δ-cadinene — a small difference, and both figures are estimates, so don’t read too much into it.
Where else you meet it
Apple skin, hops, and the pheromones of many insects. Its oxidation is the cause of superficial scald on apple skins during long cold storage.
About the boiling-point figure
Boiling points of heavy molecules are often published at reduced pressure without the pressure being stated, because at atmospheric pressure many of them decompose before they boil. The value here is an estimate converted to atmospheric pressure, used to place the compound on the volatility axis, not a measurement. Why this detail matters