2-Hexylcyclopentanone (CAS 13074-65-2) — Green Middle-top Note Fragrance Ingredient
2-Hexylcyclopentanone
CAS 13074-65-2
What Is 2-Hexylcyclopentanone?
2-Hexylcyclopentanone is a synthetic fragrance ingredient used to create fresh, green, and slightly fruity notes in perfumes and scented products. You’ll encounter it in modern floral and citrus fragrances, as well as some household cleaners for its uplifting quality. This molecule matters because it provides perfumers with a versatile building block that bridges floral and fruity accords, helping create contemporary scent profiles without relying solely on natural extracts.
Safety Profile
GENERALLY SAFEWhat Does 2-Hexylcyclopentanone Smell Like?
2-Hexylcyclopentanone opens with a crisp, green freshness reminiscent of crushed stems and dewy leaves, quickly revealing a subtle fruity undertone akin to underripe melon or pear skin. As it evolves, the heart develops a clean, slightly waxy character similar to fresh cucumber flesh, while maintaining a transparent quality. The dry-down is remarkably persistent for its molecular weight, leaving a faint musky-herbaceous trail that blends well with woody bases. Its odor profile sits intriguingly between traditional green notes and modern aquatic accords.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to enhance the crisp, aristocratic greenness of the violet leaf and iris, adding a contemporary fruity-linen freshness that modernizes this classic fougère structure.
Jean-Claude Ellena employs 2-hexylcyclopentanone to create the illusion of sliced green mango, contributing to the perfume’s innovative ‘transparent fruity’ accord that avoids sweetness.
2D Molecular Structure
SMILES: CCCCCCC1CCCC1=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Hexylcyclopentanone belongs to the aliphatic cyclic ketone class, featuring a five-membered ring with a hexyl side chain at the 2-position. While not found in nature, its structure mimics certain macrocyclic musk precursors. Industrial synthesis typically involves cyclization of appropriate aliphatic precursors or oxidation of corresponding alcohols. The molecule’s relatively compact size contributes to its moderate volatility and diffusion properties.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~210-220 °C (estimated) |
| Density | ~0.85 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Green-fruity modifier |
| Functional Fragrance | 0.1-1% | Up to 2% | Freshness booster |
Classic Accords
Tip: Use to bridge green and fruity notes in modern compositions where you want freshness without citrus or excessive sweetness.
Alternatives & Comparisons
For brighter, more explicitly fruity effects with similar fresh-green undertones but higher volatility.
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
Not currently evaluated by RIFM, but structurally similar compounds show low concern.
Sustainability
As a synthetic material, 2-hexylcyclopentanone offers consistent quality without agricultural impacts. Production typically involves petrochemical feedstocks, though emerging bio-based routes could improve sustainability. Its efficiency at low concentrations reduces overall formula load.
Explore 2-Hexylcyclopentanone
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Bauer, K. et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID90864355
Physical Properties
| Molecular Weight | 168.28 g/mol🔬 EPA CompTox |
| Density | 0.882 g/cm^3🔬 EPA CTX |
| Boiling Point | 270.85 °C🔬 EPA CTX |
| Melting Point | 17.414 °C📊 OPERA |
| Flash Point | 108.5 °C🔬 EPA CTX |
| Refractive Index | 1.453 Dimensionless📊 OPERA |
| Molar Volume | 188.812 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.9 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.478 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.478 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.72 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.016 mmHg🔬 EPA CTX |
| Viscosity | 2.6 cP📊 OPERA |
| Surface Tension | 31.02 dyn/cm📊 OPERA |
| Thermal Conductivity | 135.653 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 | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 51.047 cm^3/mol📊 OPERA |
| Polarizability | 20.237 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.
