(E)-Hex-3-enyl isobutyrate (CAS 84682-20-2) — Green Top to mid Note Fragrance Ingredient
(E)-Hex-3-enyl isobutyrate
CAS 84682-20-2
What Is (E)-Hex-3-enyl isobutyrate?
(E)-Hex-3-enyl isobutyrate is a synthetic fragrance ingredient commonly found in fresh, green perfumes and household products like air fresheners. It contributes to the crisp, natural scent of cut grass and leaves. This molecule matters because it helps recreate authentic green notes without using natural extracts, making fragrances more sustainable and consistent in quality.
Safety Profile
GENERALLY SAFEWhat Does (E)-Hex-3-enyl isobutyrate Smell Like?
A vibrant burst of freshly crushed green leaves with a juicy, slightly fruity undertone. Opens with a sharp, diffusive greenness reminiscent of snapping a celery stalk, evolving into a softer herbal heart with a whisper of unripe banana. The dry-down reveals a clean, slightly waxy character like the underside of a magnolia leaf, with excellent tenacity for a green note.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a modern green accent to complement galbanum, creating the iconic crushed-leaf effect in this groundbreaking green floral.
Provides the crisp green mango leaf note that defines this watery garden composition.
2D Molecular Structure
SMILES: CC\C=C\CCOC(=O)C(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
An ester formed from (E)-hex-3-en-1-ol (leaf alcohol) and isobutyric acid. Synthesized via acid-catalyzed esterification, often using p-toluenesulfonic acid as catalyst. The trans (E) configuration is essential for the characteristic green odor; the cis isomer smells markedly different. This synthetic route allows for high purity and consistent olfactory performance compared to natural extracts.
Physical & Chemical Properties
| Boiling Point | ~200 °C (estimated) |
|---|---|
| Density | ~0.88 g/cm³ (estimated) |
| Vapor Pressure | Low (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Green note modifier |
| Functional Fragrances | 0.1-0.5% | Up to 1% | Freshness booster |
| Household Products | 0.05-0.2% | Up to 0.5% | Clean green accent |
Classic Accords
Tip: Stabilize with antioxidants to prevent oxidation of the double bond during storage.
Alternatives & Comparisons
For a sharper, more intense green effect without the fruity ester character.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions (as of Amendment 51).
RIFM Assessment
RIFM assessment confirms safe use at current industry levels.
Sustainability
Synthetic production avoids agricultural land use and seasonal variability of natural sources. The manufacturing process has moderate energy requirements but benefits from high atom economy in esterification. Biodegradation studies show rapid breakdown in aquatic environments.
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References
- Arctander, S. (1969). Perfume and Flavor Chemicals. Allured Publishing.
- Brenna, E. et al. (2003). Biocatalyzed synthesis of flavor esters. Journal of Agricultural and Food Chemistry. DOI:10.1021/jf0260698
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 84682-20-2Physical Properties
| Molecular Weight | 170.25 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.9🔬 PubChem |
| Boiling Point | 210 °C🔬 EPA CompTox |
| Vapor Pressure | 0.3548 mmHg @ 25°C📊 OPERA |
| Flash Point | 75 °C🔬 EPA CompTox |
| Involatility Index | 0.0293💻 Calculated |
| log Kp (skin permeability) | -1.68💻 Calculated |
| SMILES | CCC=CCCOC(=O)C(C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.8 / 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: DTXSID001291757
Physical Properties
| Molecular Weight | 170.252 g/mol🔬 EPA CompTox |
| Density | 0.887 g/cm^3📊 OPERA |
| Boiling Point | 206.947 °C📊 OPERA |
| Melting Point | -54.505 °C📊 OPERA |
| Flash Point | 74.091 °C📊 OPERA |
| Refractive Index | 1.438 Dimensionless📊 OPERA |
| Molar Volume | 191.076 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.251 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.251 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.251 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.85 Log10 unitless📊 OPERA |
| Water Solubility | 0.003 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.251 mmHg📊 OPERA |
| Viscosity | 1.345 cP📊 OPERA |
| Surface Tension | 26.666 dyn/cm📊 OPERA |
| Thermal Conductivity | 133.608 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 | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 50.169 cm^3/mol📊 OPERA |
| Polarizability | 19.888 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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