5,9-Undecadienal, 2,6,10-trimethyl- (dihydroapofarnesal) (CAS 24048-13-3) — Green Top to middle Note Fragrance Ingredient
5,9-Undecadienal, 2,6,10-trimethyl- (dihydroapofarnesal)
CAS 24048-13-3
What Is 5,9-Undecadienal, 2,6,10-trimethyl- (dihydroapofarnesal)?
5,9-Undecadienal, 2,6,10-trimethyl- is a synthetic fragrance ingredient known for its unique aldehyde character. It’s found in niche perfumes and some high-end body care products. This molecule contributes a fresh, marine-like quality with floral undertones, often used to create modern, airy accords in perfumery.
Safety Profile
USE WITH AWARENESSWhat Does 5,9-Undecadienal, 2,6,10-trimethyl- (dihydroapofarnesal) Smell Like?
This aldehyde delivers a crisp, ozone-like freshness reminiscent of sea spray meeting coastal vegetation. The initial burst is sharply green with metallic edges, evolving into a softer floral heart with hints of cyclamen and lily-of-the-valley. The dry-down reveals a subtle woody-ambergris character that lingers close to the skin, creating an effect like sun-warmed driftwood. Its marine facets are less salty than calone, more organic and complex.
2D Molecular Structure
SMILES: CC(CC\C=C(/C)CCC=C(C)C)C=O
Chemistry, Properties & Perfumer Guide
The Chemistry
As a branched unsaturated aldehyde, 5,9-undecadienal belongs to the same chemical family as farnesal but with a shorter carbon chain. Its synthesis typically involves Wittig reactions or selective hydrogenation of longer-chain precursors. The molecule’s reactivity makes it challenging to work with, requiring careful pH control during formulation to prevent polymerization or degradation.
Physical & Chemical Properties
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Used as marine-floral modifier |
| Body Care | 0.05-0.2% | Up to 0.3% | Adds freshness to shower gels |
Classic Accords
Tip: Stabilize in ethanol before adding to aqueous systems to prevent degradation.
Alternatives & Comparisons
Similar floral-aldehyde character but with greater tenacity and fuller body, though less marine freshness.
More ozonic and diffusive, lacking the floral nuances but easier to work with in formulations.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
RIFM Assessment
Limited safety data available; recommended usage levels based on structural analogs.
Sustainability
As a synthetic material, production requires petrochemical feedstocks but at relatively small scale. No known ecological concerns regarding biodegradation, though full lifecycle assessments are lacking for this specific molecule.
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Ingredient Data Sheet
CAS 24048-13-3Physical Properties
| Molecular Weight | 208.34 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 4.4🔬 PubChem |
| Boiling Point | 249 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0501 mmHg @ 25°C📊 OPERA |
| Flash Point | 134.7 °C🔬 EPA CompTox |
| Involatility Index | 0.0037💻 Calculated |
| log Kp (skin permeability) | -0.847💻 Calculated |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.9 / 5💻 Calculated |
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: DTXSID2051897
Physical Properties
| Molecular Weight | 208.345 g/mol🔬 EPA CompTox |
| Density | 0.847 g/cm^3📊 OPERA |
| Boiling Point | 267.22 °C📊 OPERA |
| Melting Point | 13.518 °C📊 OPERA |
| Flash Point | 114.511 °C📊 OPERA |
| Refractive Index | 1.46 Dimensionless📊 OPERA |
| Molar Volume | 244.157 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.733 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.733 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.733 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.9 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.019 mmHg📊 OPERA |
| Viscosity | 2.936 cP📊 OPERA |
| Surface Tension | 26.502 dyn/cm📊 OPERA |
| Thermal Conductivity | 134.811 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 | 66.856 cm^3/mol📊 OPERA |
| Polarizability | 26.504 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.
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