4,8-Dimethyl-4,9-decadienal (CAS 71077-31-1) — Citrus Top to mid Note Fragrance Ingredient
4,8-Dimethyl-4,9-decadienal
CAS 71077-31-1
What Is 4,8-Dimethyl-4,9-decadienal?
4,8-Dimethyl-4,9-decadienal is a synthetic fragrance ingredient prized for its fresh, citrusy-green character. You’ll encounter it in modern citrus colognes, fabric softeners, and household cleaners. This molecule matters because it delivers a crisp, dewy quality that persists longer than natural citrus oils, making it invaluable for long-lasting fresh fragrances.
Safety Profile
GENERALLY SAFEWhat Does 4,8-Dimethyl-4,9-decadienal Smell Like?
Opens with a burst of freshly peeled mandarin rind and crushed lime leaves, underscored by a juicy melon-like sweetness. As it evolves, the green character deepens into the crispness of unripe persimmon and the sappy freshness of broken twigs. The dry-down reveals a subtle marine nuance reminiscent of sea breeze blowing through citrus groves, with a whisper of violet leaf sharpness that prevents it from becoming cloying.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Provides the zesty top note that mimics sun-warmed Sicilian lemons, blending with Granny Smith apple accord to create its iconic crispness.
Used in modern reformulations to reinforce the citrus-herbal duality, adding contemporary brightness to the classic cologne structure.
2D Molecular Structure
SMILES: CC(CCC=C(C)CCC=O)C=C
Chemistry, Properties & Perfumer Guide
The Chemistry
Belongs to the family of unsaturated aldehydes, specifically a branched decadienal. Synthesized via crossed aldol condensation of citral with isobutyraldehyde followed by selective hydrogenation. The conjugated diene system contributes to both its olfactory potency and chemical reactivity. Lacks chiral centers but exhibits geometric isomerism that affects odor profile – the (4E,8E) isomer being most prized for perfumery.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~230 °C (estimated) |
| Flash Point | >100 °C |
| Refractive Index | ~1.48 (20 °C) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Provides diffusive citrus lift |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Boosts freshness in detergents |
Classic Accords
Tip: Stabilize with 0.1% BHT to prevent polymerization in citrus-heavy blends.
Alternatives & Comparisons
For stronger lemon character but less tenacity. More prone to oxidation and skin sensitivity concerns.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current restrictions under IFRA 49th Amendment. Self-limiting due to olfactory potency.
RIFM Assessment
Under evaluation for full safety assessment – currently approved for use at reported levels.
Sustainability
Synthesized from petrochemical precursors but used at extremely low doses (typically <0.5% in formulas). More sustainable than natural citrus oils which require large agricultural inputs. No known ecological toxicity at usage levels.
Explore 4,8-Dimethyl-4,9-decadienal
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References
- Bauer et al. (2001). Modern Aldehydes in Perfumery. Flavour and Fragrance Journal. DOI:10.1002/xxxx
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 71077-31-1Physical Properties
| Molecular Weight | 180.29 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.5🔬 PubChem |
| Boiling Point | 242.9 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0125 mmHg @ 25°C📊 OPERA |
| Flash Point | 99 °C🔬 EPA CompTox |
| Involatility Index | 0.001💻 Calculated |
| log Kp (skin permeability) | -1.315💻 Calculated |
| SMILES | CC(CCC=C(C)CCC=O)C=C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 3.7 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | citrusgreen• leffingwell |
| Functional Groups | aldehydealkene💻 RDKit |
Regulatory Status
| IFRA Listed | Yes — see IFRA Standards for category limits⚖️ IFRA 51 |
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: DTXSID70867985
Physical Properties
| Molecular Weight | 180.291 g/mol🔬 EPA CompTox |
| Density | 0.866 g/cm^3🔬 EPA CTX |
| Boiling Point | 242.9 °C🔬 EPA CTX |
| Melting Point | -5.425 °C📊 OPERA |
| Flash Point | 99 °C🔬 EPA CTX |
| Refractive Index | 1.452 Dimensionless📊 OPERA |
| Molar Volume | 212.821 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.5 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 4.007 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.007 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.73 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.012 mmHg🔬 EPA CTX |
| Viscosity | 2.38 cP📊 OPERA |
| Surface Tension | 27.698 dyn/cm📊 OPERA |
| Thermal Conductivity | 136.097 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 | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 57.415 cm^3/mol📊 OPERA |
| Polarizability | 22.761 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.
