2-Hexen-1-ol (CAS 2305-21-7) — Green Top Note Fragrance Ingredient
2-Hexen-1-ol
CAS 2305-21-7
What Is 2-Hexen-1-ol?
2-Hexen-1-ol is a synthetic alcohol with a fresh, green, leafy scent. It’s often used in perfumes, soaps, and detergents to add a natural, grassy note. This ingredient matters because it helps create realistic green fragrances, mimicking the smell of freshly cut grass or leaves, enhancing the natural feel of many products.
Safety Profile
GENERALLY SAFEWhat Does 2-Hexen-1-ol Smell Like?
2-Hexen-1-ol has a sharp, green, leafy scent with a slightly fatty undertone. It evokes the smell of freshly crushed leaves or a newly mowed lawn. The scent is crisp and clean, with a slight vegetable-like quality that adds depth to green fragrances. Over time, it mellows into a softer, more herbal note, blending well with other green and woody ingredients.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the fresh, green top notes, adding a realistic leafy quality that complements the violet and iris heart.
Adds a crisp, green edge to the mango and grapefruit opening, mimicking the scent of lush riverbank vegetation.
2D Molecular Structure
SMILES: CCCC=CCO
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Hexen-1-ol is a six-carbon unsaturated alcohol with a double bond at the 2-position. It is typically synthesized via the hydroformylation of 1,3-butadiene followed by hydrogenation. This compound is part of the green leaf volatiles (GLVs) family, which are emitted by plants as a defense mechanism. Its structure allows it to contribute both fresh and slightly fatty olfactory characteristics.
Physical & Chemical Properties
| Boiling Point | 156-158 °C |
|---|---|
| Density | 0.84 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | Adds fresh green top notes |
| Soap/Detergent | 0.5-2% | Up to 3% | Enhances clean, natural scents |
Classic Accords
Tip: Use in small amounts to avoid overpowering the blend with its sharp green character.
Alternatives & Comparisons
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA standards.
EU Allergen Declaration
Not listed as an EU allergen.
GHS Classification
RIFM Assessment
RIFM safety assessment confirms safe use at current levels in fragrances.
Sustainability
2-Hexen-1-ol is typically synthesized from petrochemical sources, but efforts are underway to produce it via bio-based routes using renewable feedstocks. Its environmental impact is moderate, with standard precautions for handling and disposal.
Explore 2-Hexen-1-ol
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 2-Hexen-1-ol CID 5281168
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 2305-21-7Physical Properties
| Molecular Weight | 100.16 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.4🔬 PubChem |
| Boiling Point | 158 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -2.317💻 Calculated |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
Odor & Flavor
| Primary Descriptors | fruitygreenleafysharp• leffingwell |
| 2-Hexen-1-ol has a powerful, leafy, green, wine-like, fruity odor, with a sweet, fruity flavor important to strawberry and orange juice.📖 Fenaroli | |
Regulatory Status
| IOFI Classification | Nature Identical📖 Fenaroli |
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: DTXSID3051882
Physical Properties
| Molecular Weight | 100.161 g/mol🔬 EPA CompTox |
| Density | 0.839 g/cm^3🔬 EPA CTX |
| Boiling Point | 158 °C🔬 EPA CTX |
| Melting Point | -26.384 °C📊 OPERA |
| Flash Point | 60.345 °C📊 OPERA |
| Refractive Index | 1.443 Dimensionless📊 OPERA |
| Molar Volume | 118.697 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.6 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.331 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.331 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.65 Log10 unitless📊 OPERA |
| Water Solubility | 0.129 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.626 mmHg📊 OPERA |
| Viscosity | 2.304 cP📊 OPERA |
| Surface Tension | 27.005 dyn/cm📊 OPERA |
| Thermal Conductivity | 151.552 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 20.23 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 31.439 cm^3/mol📊 OPERA |
| Polarizability | 12.463 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.
