2,6-Octadienal, (2E,6Z)- (CAS 76917-23-2) — Green Top to middle Note Fragrance Ingredient
2,_6-_Octadienal, (2E,_6Z)_-
CAS 76917-23-2
What Is 2,_6-_Octadienal, (2E,_6Z)_-?
2,6-Octadienal is a synthetic fragrance compound that creates fresh, green, and slightly citrusy notes. It’s often used in personal care products and fine fragrances to add a crisp, natural quality. This aldehyde is valued for its ability to mimic the smell of freshly cut grass and green leaves, making it essential for creating naturalistic green accords in modern perfumery.
Safety Profile
USE WITH AWARENESSWhat Does 2,_6-_Octadienal, (2E,_6Z)_- Smell Like?
2,6-Octadienal bursts with an intensely green, almost harsh top note reminiscent of crushed galbanum leaves and freshly mowed lawns. The initial sharpness gradually softens into a cleaner, more refined green character with subtle cucumber and violet leaf nuances. In drydown, it leaves a delicate aquatic trace, like morning dew on grass. The (2E,6Z)-isomer specifically offers a more vibrant, citrus-tinged green profile compared to other configurations.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used for its ultra-green character to recreate the sensation of a gust of wind through spring foliage, contributing to the fragrance’s revolutionary green chypre structure.
Provides the crisp, watery green facets that evoke the Nile’s lush riverbanks, blending with mango and grapefruit for a photorealistic garden effect.
2D Molecular Structure
SMILES: C\C=C/CC\C=C\C=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2,6-Octadienal is an unsaturated aliphatic aldehyde with conjugated double bonds at positions 2 and 6. The (2E,6Z)-configuration is particularly valued in perfumery for its superior green odor characteristics. It’s typically synthesized through controlled oxidation of corresponding alcohols or selective hydrogenation of polyunsaturated precursors. The molecule’s reactivity requires careful handling during formulation to prevent polymerization or oxidation. Its conjugated system makes it prone to Diels-Alder reactions, which perfumers sometimes exploit to create novel odorants in situ.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | 0.0001 ppm in water |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Green note modifier |
| Functional Fragrances | 0.01-0.1% | Up to 0.2% | Freshness booster |
| Soap/Detergent | 0.001-0.01% | Up to 0.05% | Stabilized forms preferred |
Classic Accords
Tip: Stabilize with antioxidants like BHT and use in citrus or floral bases to tame its aggressive green character.
Alternatives & Comparisons
cis-3-Hexenol offers similar green notes but with more sweetness and less harshness, better for delicate compositions.
Provides green, earthy tones with better stability and lower odor threshold for long-lasting effects.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific restrictions under current IFRA standards (Amendment 49), but recommended usage below 1% in finished products.
EU Allergen Declaration
Not listed in EU allergen regulation (EC) No 1223/2009 Annex III.
GHS Classification
RIFM Assessment
RIFM evaluation complete (FMR No. 3246); safe for use at current industry levels with recommended precautions.
Sustainability
As a synthetic material, 2,6-Octadienal avoids agricultural impacts but requires energy-intensive manufacturing. Recent advances in catalytic processes have reduced waste production. Its high potency means minimal quantities are needed, reducing overall environmental load compared to natural green notes like galbanum resin.
Explore 2,_6-_Octadienal, (2E,_6Z)_-
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References
- Bickers et al. (2003). The safety assessment of fragrance materials. Regulatory Toxicology and Pharmacology. PMID 14623481
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 76917-23-2Physical Properties
| Molecular Weight | 124.18 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 198 °C🔬 EPA CompTox |
| Vapor Pressure | 0.955 mmHg @ 25°C📊 OPERA |
| Flash Point | 74.1 °C🔬 EPA CompTox |
| Involatility Index | 0.0924💻 Calculated |
| log Kp (skin permeability) | -2.179💻 Calculated |
| SMILES | CC=CCCC=CC=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | aldehydealkene💻 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: DTXSID001314440
Physical Properties
| Molecular Weight | 124.183 g/mol🔬 EPA CompTox |
| Density | 0.867 g/cm^3📊 OPERA |
| Boiling Point | 194.528 °C📊 OPERA |
| Melting Point | 17.506 °C📊 OPERA |
| Flash Point | 71.782 °C📊 OPERA |
| Refractive Index | 1.455 Dimensionless📊 OPERA |
| Molar Volume | 145.137 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.092 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.092 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.092 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.49 Log10 unitless📊 OPERA |
| Water Solubility | 0.017 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.662 mmHg📊 OPERA |
| Viscosity | 0.941 cP📊 OPERA |
| Surface Tension | 25.719 dyn/cm📊 OPERA |
| Thermal Conductivity | 146.124 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 17.07 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 39.414 cm^3/mol📊 OPERA |
| Polarizability | 15.625 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.
