2,4-Dimethylcyclohex-3-ene-1-methyl acetate (CAS 67634-26-8) — Green Top to middle Note Fragrance Ingredient
2,4-Dimethylcyclohex-3-ene-1-methyl acetate
CAS 67634-26-8
What Is 2,4-Dimethylcyclohex-3-ene-1-methyl acetate?
2,4-Dimethylcyclohex-3-ene-1-methyl acetate is a synthetic fragrance ingredient used in modern perfumery to add fresh, green, and slightly woody nuances. It’s found in many contemporary fragrances, especially those aiming for a crisp, natural effect. This molecule matters because it helps perfumers create airy, outdoor-like accords without relying solely on natural extracts, offering consistency and sustainability advantages.
Safety Profile
GENERALLY SAFEWhat Does 2,4-Dimethylcyclohex-3-ene-1-methyl acetate Smell Like?
This synthetic molecule opens with a burst of crisp, dewy greenness reminiscent of crushed stems and morning foliage. The initial sharpness quickly settles into a smoother, slightly woody character with hints of damp earth. As it evolves, a subtle fruity undertone emerges – imagine unripe pears mingling with fresh-cut cedar. The dry-down is remarkably clean, leaving a faint herbal trace that blends seamlessly with other notes.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the naturalistic green accord, providing structural support to the citrus top notes while preventing the composition from becoming too sweet.
Employed as a green bridge between the sharp grapefruit opening and the soft woody base, creating the illusion of floating lotus stems.
2D Molecular Structure
SMILES: CC1C=C(C)CCC1COC(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2,4-Dimethylcyclohex-3-ene-1-methyl acetate belongs to the cyclohexene ester class, synthesized through esterification of dimethylcyclohexenol with acetic anhydride. The molecule features a constrained cyclohexene ring with two methyl groups creating steric hindrance, which influences its volatility and odor characteristics. Industrial synthesis typically involves acid-catalyzed reactions under controlled conditions to minimize rearrangement byproducts.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | 0.5 ppb in air |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Green modifier |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Freshness booster |
Classic Accords
Tip: Use to extend the longevity of natural green notes while maintaining transparency in the composition.
Alternatives & Comparisons
Offers similar green character but with more pronounced herbal aspects and better diffusion.
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
Under evaluation by RIFM, preliminary data suggests low toxicity risk.
Sustainability
As a synthetic material, this ingredient avoids agricultural land use and seasonal variability. Production typically uses petrochemical feedstocks, though some manufacturers are exploring bio-based routes. Its potency means relatively small quantities are needed in formulations.
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References
- Bauer et al. (2001). Modern Synthetic Materials in Perfumery. Perfumer & Flavorist.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 67634-26-8Physical Properties
| Molecular Weight | 182.26 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.1🔬 PubChem |
| Boiling Point | 236.3 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1358 mmHg @ 25°C📊 OPERA |
| Flash Point | 85 °C🔬 EPA CompTox |
| Involatility Index | 0.0108💻 Calculated |
| log Kp (skin permeability) | -2.321💻 Calculated |
| SMILES | CC1C=C(CCC1COC(=O)C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 1.4 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | greenwoody• leffingwell |
| Functional Groups | esteretheralkene💻 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: DTXSID2052364
Physical Properties
| Molecular Weight | 182.263 g/mol🔬 EPA CompTox |
| Density | 0.965 g/cm^3🔬 EPA CTX |
| Boiling Point | 236.3 °C🔬 EPA CTX |
| Melting Point | -9.484 °C📊 OPERA |
| Flash Point | 85 °C🔬 EPA CTX |
| Refractive Index | 1.449 Dimensionless📊 OPERA |
| Molar Volume | 195.284 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.2 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.581 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.581 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.7 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.136 mmHg🔬 EPA CTX |
| Viscosity | 3.464 cP📊 OPERA |
| Surface Tension | 28.425 dyn/cm📊 OPERA |
| Thermal Conductivity | 130.989 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 52.421 cm^3/mol📊 OPERA |
| Polarizability | 20.781 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.
