Isolongifolene oxide (CAS 26619-69-2) — Woody Middle to base Note Fragrance Ingredient
Isolongifolene oxide
CAS 26619-69-2
What Is Isolongifolene oxide?
Isolongifolene oxide is a synthetic fragrance ingredient primarily encountered in modern perfumery and functional fragrances. It contributes woody, amber-like nuances to compositions. This molecule matters as it provides stability and longevity to fragrance formulas while offering a cost-effective alternative to rare natural materials with similar olfactory profiles.
Safety Profile
USE WITH AWARENESSWhat Does Isolongifolene oxide Smell Like?
Isolongifolene oxide presents a complex olfactory profile that evolves from initial crisp, slightly camphoraceous top notes to reveal a heart of dry woody character with subtle amber undertones. The dry-down exhibits remarkable tenacity, leaving a trace of warm, slightly resinous musk that lingers close to the skin. Its odor profile bridges the gap between traditional woody ambers and modern synthetic musks, with a clean, almost mineralic quality that prevents it from becoming overly sweet or heavy.
2D Molecular Structure
SMILES: CC1(C)[C@H]2CC[C@]3(C2)[C@@]11O[C@@H]1CCC3(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Isolongifolene oxide belongs to the sesquiterpene oxide class, derived through the oxidation of isolongifolene, a tricyclic sesquiterpene hydrocarbon. While not found in significant quantities in nature, it is synthesized industrially via catalytic oxidation processes. The molecule’s rigid tricyclic structure contributes to its stability and slow evaporation rate. The oxygen bridge introduces polarity while maintaining the hydrocarbon’s hydrophobic character, resulting in unique solubility properties that influence its performance in fragrance applications.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Strength | Medium to strong |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Used as woody-amber modifier |
| Functional Fragrances | 0.1-1% | Up to 2% | Provides longevity in detergents |
Classic Accords
Tip: Use with citrus top notes to prevent the dry-down from becoming too heavy.
Alternatives & Comparisons
More diffusive but less tenacious woody-amber alternative with similar structural rigidity.
Provides more pronounced woody character with higher impact but less subtlety.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current IFRA restrictions. Listed on IFRA Transparency List.
RIFM Assessment
Under review by RIFM. Preliminary data suggests low sensitization potential.
Sustainability
As a synthetic material, isolongifolene oxide offers consistent quality without natural sourcing constraints. Production typically involves catalytic oxidation of renewable petrochemical feedstocks, with relatively low environmental impact compared to extraction processes for natural alternatives. Its stability reduces the need for frequent reapplication in end products.
Explore Isolongifolene oxide
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
Perfumer’s Notes
MW: 220.35
LogP: 3.8
Ingredient Data Sheet
CAS 26619-69-2Physical Properties
| Molecular Weight | 220.35 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.8🔬 PubChem |
| Boiling Point | 257 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0143 mmHg @ 25°C📊 OPERA |
| Flash Point | 120 °C🔬 EPA CompTox |
| Involatility Index | 0.001💻 Calculated |
| log Kp (skin permeability) | -1.346💻 Calculated |
| SMILES | CC1(CCC2C3(C14CCC(C4)C3(C)C)O2)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 3.9 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | ether💻 RDKit |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID50885364
Physical Properties
| Molecular Weight | 220.356 g/mol🔬 EPA CompTox |
| Density | 0.999 g/cm^3🔬 EPA CTX |
| Boiling Point | 260.934 °C📊 OPERA |
| Melting Point | -1 °C🔬 EPA CTX |
| Flash Point | 120 °C🔬 EPA CTX |
| Refractive Index | 1.532 Dimensionless📊 OPERA |
| Molar Volume | 209.992 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.645 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.645 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.645 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.9 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.011 mmHg🔬 EPA CTX |
| Surface Tension | 35.968 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 12.53 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 65.056 cm^3/mol📊 OPERA |
| Polarizability | 25.79 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
![Bicyclo[2.2.1]heptan-2-ol, 2-ethyl-1,3,3-trimethyl-, (1R,2R,4S)- (CAS 137255-07-3) — Woody Middle Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/bicyclo-2-2-1-heptan-2-ol-2-ethyl-1-3-3-trimethyl-1-1-768x439.webp)