1,3-Cyclohexadiene-1-carboxylic acid, 4,6,6-trimethyl-, ethyl ester (CAS 100520-15-8) — Green Top to Middle Note Fragrance Ingredient
1,_3-_Cyclohexadiene-_1-_carboxylic acid, 4,_6,_6-_trimethyl-_, ethyl ester
CAS 100520-15-8
What Is 1,_3-_Cyclohexadiene-_1-_carboxylic acid, 4,_6,_6-_trimethyl-_, ethyl ester?
1,3-Cyclohexadiene-1-carboxylic acid, 4,6,6-trimethyl-, ethyl ester is a synthetic fragrance ingredient used in fine perfumery. It contributes to fresh, green, and slightly woody accords. Consumers encounter it in high-end fragrances where it enhances complexity and longevity. This compound matters because it offers perfumers a unique balance between natural freshness and synthetic stability, allowing for innovative scent designs that last longer on skin.
Safety Profile
GENERALLY SAFEWhat Does 1,_3-_Cyclohexadiene-_1-_carboxylic acid, 4,_6,_6-_trimethyl-_, ethyl ester Smell Like?
This synthetic molecule opens with a crisp, green burst reminiscent of crushed leaves and fresh-cut grass. The heart evolves into a subtle woody character, like sun-warmed cedar, while the dry-down reveals a faintly sweet, almost balsamic undertone. It behaves like a chameleon, blending seamlessly with citrus top notes while anchoring floral heart accords. The progression is linear yet nuanced, making it versatile for modern compositions.
2D Molecular Structure
SMILES: CCOC(=O)C1=CC=C(C)CC1(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
This ester belongs to the cyclohexadiene carboxylic acid family, synthesized through esterification of trimethylcyclohexadiene carboxylic acid with ethanol. The cyclohexadiene ring provides structural rigidity, contributing to its moderate volatility. The ethyl ester group enhances its solubility in common fragrance carriers. While not found in nature, its structure mimics certain terpenoid derivatives, offering a bridge between synthetic and natural olfactive effects.
Physical & Chemical Properties
| Boiling Point | Not available |
|---|---|
| Density | Not available |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 10% | Adds green freshness |
| Functional Fragrances | 0.5-2% | Up to 5% | Moderate use recommended |
Classic Accords
Tip: Use in citrus or fougère compositions to enhance green character without overpowering delicate top notes.
Alternatives & Comparisons
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current IFRA restrictions.
RIFM Assessment
No specific RIFM assessment found for this compound.
Sustainability
As a synthetic ingredient, its production avoids natural resource depletion but requires petrochemical feedstocks. Future green chemistry approaches may improve its environmental profile. The ester linkage offers potential for biodegradability under appropriate conditions.
Explore 1,_3-_Cyclohexadiene-_1-_carboxylic acid, 4,_6,_6-_trimethyl-_, ethyl ester
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- PubChem Compound Summary for CID 100520-15-8 PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 100520-15-8Physical Properties
| Molecular Weight | 194.27 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.9🔬 PubChem |
| Boiling Point | 239 °C🔬 EPA CompTox |
| Vapor Pressure | 0.049 mmHg @ 25°C📊 OPERA |
| Flash Point | 106.2 °C🔬 EPA CompTox |
| Involatility Index | 0.0038💻 Calculated |
| log Kp (skin permeability) | -1.826💻 Calculated |
| SMILES | CCOC(=O)C1=CC=C(CC1(C)C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.4 / 5💻 Calculated |
Odor & Flavor
| 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: DTXSID50738528
Physical Properties
| Molecular Weight | 194.274 g/mol🔬 EPA CompTox |
| Density | 0.969 g/cm^3📊 OPERA |
| Boiling Point | 242.904 °C📊 OPERA |
| Melting Point | 29.407 °C📊 OPERA |
| Flash Point | 101.467 °C📊 OPERA |
| Refractive Index | 1.472 Dimensionless📊 OPERA |
| Molar Volume | 201.551 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.791 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.791 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.791 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.75 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.026 mmHg📊 OPERA |
| Surface Tension | 30.115 dyn/cm📊 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 | 56.483 cm^3/mol📊 OPERA |
| Polarizability | 22.391 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.
![5H-Cyclopenta[h]quinazoline, 6,6a,7,8,9,9a-hexahydro-7,7,8,9,9-pentamethyl- (CAS 1392325-86-8) — Woody Base Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/5h-cyclopenta-h-quinazoline-6-6a-7-8-9-9a-hexahydro-7-7-8-9-1-1-768x439.webp)
