(-)-.alpha.-Fenchol (CAS 512-13-0) — Green Top to Middle Note Fragrance Ingredient
(-)-.alpha.-Fenchol
CAS 512-13-0
What Is (-)-.alpha.-Fenchol?
(-)-α-Fenchol is a naturally occurring monoterpenoid alcohol found in fennel and some pine species, though most commercial versions are synthetic. It’s used as a fresh, woody-green note in perfumes and functional fragrances like soaps and detergents. This ingredient helps create crisp, natural-smelling accords that evoke pine forests and aromatic herbs. Though not widely known by name, its scent profile contributes to many modern masculine and unisex fragrances.
Safety Profile
GENERALLY SAFEWhat Does (-)-.alpha.-Fenchol Smell Like?
(-)-α-Fenchol opens with a brisk, cooling camphoraceous lift reminiscent of crushed pine needles and eucalyptus, quickly revealing a complex heart where damp earthiness meets crisp herbal facets. The dry-down evolves into a dry, woody character with subtle sweetness—like sun-warmed cedarwood with a whisper of fennel seed. Unlike its isomer (+)-fenchol, this enantiomer has sharper green tones and less sweet balsamic warmth, making it ideal for creating transparent, outdoorsy effects in fragrances.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a crisp counterpoint to vanilla and tonka, (-)-α-fenchol provides an aromatic green lift that prevents the base from becoming overly gourmand.
This classic employs (-)-α-fenchol alongside tomato leaf and galbanum to create its iconic ‘sun-baked herb garden’ effect.
Chemistry, Properties & Perfumer Guide
The Chemistry
(-)-α-Fenchol is a bicyclic monoterpene alcohol with a hydroxyl group at the bridgehead carbon, giving it unique stereochemical constraints. The (-) enantiomer occurs naturally in Foeniculum vulgare (fennel) and some Artemisia species, while industrial production typically involves hydrogenation of α-pinene oxide or microbial transformation of pinene. Its rigid norbornane-like structure contributes to exceptional stability in acidic media compared to acyclic terpene alcohols, though it remains prone to oxidation at the allylic position.
Physical & Chemical Properties
| Boiling Point | 201-202 °C |
|---|---|
| Density | 0.948 g/cm³ |
| Refractive Index | 1.472 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Adds transparent greenery |
| Functional Fragrances | 0.1-1% | Up to 2% | Freshness booster |
Classic Accords
Tip: Stabilize with 0.1% BHT to prevent oxidation during aging.
Alternatives & Comparisons
Softer, fruitier variant with better longevity; use when needing a less camphoraceous effect.
More balsamic and less green; suitable for oriental compositions requiring warmth.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA 51st Amendment.
RIFM Assessment
RIFM assessment confirms safe use at current industry levels.
Sustainability
Synthetic production from turpentine derivatives (a renewable resource) avoids agricultural impacts of wild-harvested botanicals. Major manufacturers have implemented green chemistry protocols using catalytic hydrogenation to minimize waste. Biodegradability is excellent (OECD 301F >90% in 28 days).
Explore (-)-.alpha.-Fenchol
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Bicas et al. (2010). Bio-oxidation of terpenes: an approach for the flavor industry. Chemical Reviews. PMID 20429552
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data error![Benzenemethanaminium, N-ethyl-N-[4-[[4-[ethyl[(3-sulfophenyl)methyl]amino]phenyl](4-hydroxy-2-sulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-3-sulfo-, inner salt, sodium salt (1:2) (CAS 2353-45-9) — Citrus N/A Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/benzenemethanaminium-n-ethyl-n-4-4-ethyl-1-2-768x439.webp)
![Pentanedioic acid, 1-(4-formyl-2-methoxyphenyl) 5-[(1R,2S,5R)-5-methyl-2-(1-methylethyl)cyclohexyl] ester (CAS 2308574-23-2) — Woody Heart to base Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/pentanedioic-acid-1-1-1-768x439.webp)
![[2-Isopropoxyethyl]benzene (CAS 68039-47-4) — Floral Middle Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/2-isopropoxyethyl-benzene-768x439.webp)
