2-Pentylcyclopentan-1-one (CAS 4819-67-4) — Floral Top to Middle Note Fragrance Ingredient
2-Pentylcyclopentan-1-one
CAS 4819-67-4
What Is 2-Pentylcyclopentan-1-one?
2-Pentylcyclopentan-1-one is a synthetic fragrance ingredient used in perfumes and scented products to add fruity, floral, and slightly woody notes. It is commonly found in air fresheners, detergents, and personal care products. This ingredient matters because it enhances the overall scent profile, providing a pleasant and long-lasting aroma that improves user experience.
Safety Profile
GENERALLY SAFEWhat Does 2-Pentylcyclopentan-1-one Smell Like?
2-Pentylcyclopentan-1-one offers a complex olfactory profile, starting with a fresh, fruity top note reminiscent of ripe apples and pears. As it evolves, it reveals a floral heart with hints of jasmine and rose, settling into a subtle woody base. The dry-down is smooth and slightly sweet, making it versatile for various fragrance applications.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the fruity and floral notes, providing a balanced and appealing scent.
2D Molecular Structure
SMILES: CCCCCC1CCCC1=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Pentylcyclopentan-1-one is a synthetic ketone with a cyclopentanone core and a pentyl side chain. It is produced through chemical synthesis, often involving the cyclization of appropriate precursors. The molecule’s structure contributes to its fruity and floral olfactory characteristics, making it a valuable ingredient in perfumery.
Physical & Chemical Properties
| Boiling Point | N/A |
|---|---|
| Density | N/A |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 2-5% | Up to 10% | Adds fruity and floral complexity |
| Personal Care | 1-3% | Up to 5% | Provides a pleasant scent |
Classic Accords
Tip: Use in combination with other fruity and floral notes to enhance complexity.
Alternatives & Comparisons
Offers a similar profile with a slightly longer-lasting effect.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current IFRA restrictions.
EU Allergen Declaration
Not listed as an EU allergen.
RIFM Assessment
No specific RIFM safety assessment found.
Sustainability
As a synthetic ingredient, 2-Pentylcyclopentan-1-one is produced in controlled environments, reducing the environmental impact compared to natural extraction. Its production can be optimized for minimal waste and energy use.
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References
- PubChem Compound Summary for 2-Pentylcyclopentan-1-one PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 4819-67-4Physical Properties
| Molecular Weight | 154.25 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.9🔬 PubChem |
| Boiling Point | 220.9 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1155 mmHg @ 25°C📊 OPERA |
| Flash Point | 89.8 °C🔬 EPA CompTox |
| Involatility Index | 0.01💻 Calculated |
| log Kp (skin permeability) | -1.582💻 Calculated |
| SMILES | CCCCCC1CCCC1=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 1.6 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | ketone💻 RDKit |
Trade Names
| Fleuramone (IFF), Projasmon P (Symrise).📖 Surburg |
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: DTXSID1044566
Physical Properties
| Molecular Weight | 154.253 g/mol🔬 EPA CompTox |
| Density | 0.89 g/cm^3🔬 EPA CTX |
| Boiling Point | 220.85 °C🔬 EPA CTX |
| Melting Point | 9.992 °C📊 OPERA |
| Flash Point | 85.6 °C🔬 EPA CTX |
| Refractive Index | 1.451 Dimensionless📊 OPERA |
| Molar Volume | 172.306 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.28 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.976 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.976 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.24 Log10 unitless📊 OPERA |
| Water Solubility | 0.004 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.116 mmHg🔬 EPA CTX |
| Viscosity | 2.003 cP📊 OPERA |
| Surface Tension | 30.792 dyn/cm📊 OPERA |
| Thermal Conductivity | 133.634 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 | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 46.414 cm^3/mol📊 OPERA |
| Polarizability | 18.4 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.
