6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde (CAS 33885-51-7) — Woody Top to middle Note Fragrance Ingredient
6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde
CAS 33885-51-7
What Is 6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde?
6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde is a synthetic fragrance ingredient used in modern perfumery. It contributes fresh, woody, and slightly pine-like notes to compositions. This molecule is found in various personal care products and fine fragrances, often used to enhance natural forest accords.
Safety Profile
GENERALLY SAFEWhat Does 6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde Smell Like?
This aldehyde delivers a crisp, woody-pine character with subtle citrus undertones. The initial burst is fresh and slightly camphoraceous, evolving into a cleaner woody heart. The dry-down reveals a soft, ambery warmth with excellent tenacity. Imagine walking through a sun-dappled pine forest where the resinous bark meets morning dew.
2D Molecular Structure
SMILES: CC1(C)C2CC1C(CCC=O)=CC2
Chemistry, Properties & Perfumer Guide
The Chemistry
6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde belongs to the bicyclic monoterpene aldehyde class. It’s synthesized through oxidation of pinene derivatives or Diels-Alder reactions. The rigid bicyclic structure contributes to its stability and distinctive odor profile. The aldehyde group provides reactivity while the dimethyl substitution enhances volatility.
Physical & Chemical Properties
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Woody-pine modifier |
| Functional Fragrances | 0.1-0.5% | Up to 1% | Freshness booster |
Classic Accords
Tip: Use with citrus top notes to enhance freshness without excessive sharpness.
Alternatives & Comparisons
Similar pine character but more herbal and less sweet. Useful when needing sharper green notes.
Offers comparable woody-pine aspects with additional minty freshness for cooling effects.
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
No RIFM assessment publicly available.
Sustainability
As a synthetic material, this compound avoids natural resource depletion. Production typically uses pinene derivatives from renewable turpentine sources. Energy-efficient catalytic processes minimize environmental impact compared to traditional synthesis routes.
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Ingredient Data Sheet
CAS 33885-51-7Physical Properties
| Molecular Weight | 178.27 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.2🔬 PubChem |
| Boiling Point | 243.9 °C🔬 EPA CompTox |
| Vapor Pressure | 0.033 mmHg @ 25°C📊 OPERA |
| Flash Point | 97 °C🔬 EPA CompTox |
| Involatility Index | 0.0027💻 Calculated |
| log Kp (skin permeability) | -2.225💻 Calculated |
| SMILES | CC1(C2CC=C(C1C2)CCC=O)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.4 / 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: DTXSID7052022
Physical Properties
| Molecular Weight | 178.275 g/mol🔬 EPA CompTox |
| Density | 0.961 g/cm^3🔬 EPA CTX |
| Boiling Point | 243.9 °C🔬 EPA CTX |
| Melting Point | 27.318 °C📊 OPERA |
| Flash Point | 97 °C🔬 EPA CTX |
| Refractive Index | 1.485 Dimensionless📊 OPERA |
| Molar Volume | 186.31 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.3 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.326 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.326 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.77 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.033 mmHg🔬 EPA CTX |
| Viscosity | 1.549 cP📊 OPERA |
| Surface Tension | 30.171 dyn/cm📊 OPERA |
| Thermal Conductivity | 123.633 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 | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 53.402 cm^3/mol📊 OPERA |
| Polarizability | 21.17 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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