2-Ethylidenedecan-1-al (CAS 64825-20-3) — Green Top Note Fragrance Ingredient
2-Ethylidenedecan-1-al
CAS 64825-20-3
What Is 2-Ethylidenedecan-1-al?
2-Ethylidenedecan-1-al is a synthetic fragrance ingredient used to add a modern, clean freshness to perfumes. You’ll encounter it in laundry detergents, fabric softeners, and some contemporary floral perfumes. It’s valued for its ability to enhance ‘just washed’ impressions without overpowering other notes. This aldehyde helps create sparkling top notes in fragrances, contributing to the initial burst of scent when first applied. Its subtle marine and citrus-tinged character makes it popular in aquatic and fresh compositions.
Safety Profile
USE WITH AWARENESSWhat Does 2-Ethylidenedecan-1-al Smell Like?
2-Ethylidenedecan-1-al presents a crisp, clean odor profile reminiscent of freshly laundered linens drying in sea breeze. The opening is deceptively simple – a bright, ozonic freshness with subtle citrus undertones like the zest of green mandarin. As it develops, a delicate marine aspect emerges, not fishy but rather like the mineral tang of sea spray on warm rocks. The dry-down reveals a surprisingly soft, almost powdery quality that prevents the freshness from becoming harsh. Its tenacity is moderate, making it ideal for creating transient top notes that fade gracefully into heart accords.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the aquatic freshness, contributing to that iconic ‘blue’ fragrance character. It blends with calone and citrus to create the impression of ocean mist.
Works in harmony with Sicilian citrus to create the sparkling, sun-drenched quality. Its marine facets enhance the fragrance’s Mediterranean beach inspiration.
Helps achieve the water droplet effect in this revolutionary aquatic floral. Its clean character prevents the lotus note from becoming too heavy.
2D Molecular Structure
SMILES: CCCCCCCCC(=CC)C=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Ethylidenedecan-1-al belongs to the family of α,β-unsaturated aldehydes, characterized by a carbon-carbon double bond adjacent to the aldehyde group. This structural feature contributes to its reactivity and fresh odor profile. Industrially, it’s typically synthesized via aldol condensation reactions using decanal as a starting material. The ethylidene group at the alpha position introduces steric hindrance that affects both its odor characteristics and chemical stability. Unlike simpler aldehydes, its structure prevents rapid oxidation, giving it better shelf life in formulations while maintaining its fresh olfactory properties.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Approx. 230-240 °C (estimated) |
| Density | ~0.85 g/cm³ (estimated) |
| Solubility | Soluble in alcohol, insoluble in water |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Fresh top note component |
| Functional Fragrance | 0.1-1% | Up to 3% | Laundry and cleaning products |
| Cosmetics | 0.05-0.5% | Up to 1% | Shampoos, body washes |
Classic Accords
Tip: Use in trace amounts with citrus oils to prevent the development of waxy off-notes during aging.
Alternatives & Comparisons
Offers similar fresh qualities but with more floral character and better stability in alkaline systems. Preferred for shampoos and soaps.
Provides a more pronounced melon-like freshness when a fruitier direction is desired in aquatic compositions.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Listed on IFRA Transparency List with no usage limitations specified.
EU Allergen Declaration
Not listed in EU allergen regulation (EC) No 1223/2009 Annex III.
GHS Classification
RIFM Assessment
RIFM has reviewed safety data and established an acceptable exposure level for this material in fragrance applications.
Sustainability
As a synthetic material, 2-Ethylidenedecan-1-al production doesn’t rely on agricultural resources. Modern manufacturing processes aim to minimize solvent use and energy consumption. The material’s potency means only small quantities are needed in formulations, reducing overall environmental load compared to some natural alternatives with similar odor profiles.
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References
- Bauer, K. et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH. ISBN 978-3-527-30364-6
- IFRA Transparency List IFRA Official
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 64825-20-3Physical Properties
| Molecular Weight | 182.3 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 4.6🔬 PubChem |
| Boiling Point | 226 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0191 mmHg @ 25°C📊 OPERA |
| Flash Point | 98.3 °C🔬 EPA CompTox |
| Involatility Index | 0.0015💻 Calculated |
| log Kp (skin permeability) | -0.546💻 Calculated |
| SMILES | CCCCCCCCC(=CC)C=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 3.8 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | citrusgreen• leffingwell |
| 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: DTXSID5052331
Physical Properties
| Molecular Weight | 182.307 g/mol🔬 EPA CompTox |
| Density | 0.841 g/cm^3📊 OPERA |
| Boiling Point | 241.833 °C📊 OPERA |
| Melting Point | 15.332 °C📊 OPERA |
| Flash Point | 89.833 °C📊 OPERA |
| Refractive Index | 1.444 Dimensionless📊 OPERA |
| Molar Volume | 217.351 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.248 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.248 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.248 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.96 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.018 mmHg📊 OPERA |
| Viscosity | 2.552 cP📊 OPERA |
| Surface Tension | 26.892 dyn/cm📊 OPERA |
| Thermal Conductivity | 138.937 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 | 8 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 57.731 cm^3/mol📊 OPERA |
| Polarizability | 22.886 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.
