3-(2-Oxopropyl)-2-pentylcyclopentanone (CAS 40942-73-2) — Woody Middle Note Fragrance Ingredient

Woody · Balsamic

3-(2-Oxopropyl)-2-pentylcyclopentanone

CAS 40942-73-2

Origin
synthetic
Note
Middle
IFRA
Use with awareness
Data as of: Apr 2026

What Is 3-(2-Oxopropyl)-2-pentylcyclopentanone?

3-(2-Oxopropyl)-2-pentylcyclopentanone is a synthetic fragrance ingredient used in modern perfumery to create unique, complex scent profiles. It is typically found in niche and experimental fragrances rather than mainstream consumer products. This molecule matters because it represents perfumers’ ability to engineer novel olfactory experiences beyond nature’s palette, offering distinctive aroma characteristics that can’t be achieved with traditional materials.

Safety Profile

USE WITH AWARENESS
Generally safeUse with awarenessProfessional use
Limited safety data available
Recommended for professional formulation only
CAS
40942-73-2
Formula
Mixture
MW
Variable
Odor Family
Woody · Balsamic
Layer 1 · Enthusiast

What Does 3-(2-Oxopropyl)-2-pentylcyclopentanone Smell Like?

This synthetic molecule presents a sophisticated olfactory profile, opening with a sharp, almost metallic ketonic character that quickly evolves into a warm, leathery heart. The pentyl side chain contributes a subtle fatty nuance, while the oxopropyl group adds an intriguing lactonic dimension. As it dries down, it reveals a persistent woody-ambery base with animalic undertones, behaving like a molecular chameleon that bridges fresh top notes with deep base accords.

Scent Profile
Layer 2

2D Molecular Structure

Cyclopentanone, 3-(2-oxopropyl)-2-pentyl-

SMILES: CCCCCC1C(CC(C)=O)CCC1=O

Chemistry, Properties & Perfumer Guide

The Chemistry

3-(2-Oxopropyl)-2-pentylcyclopentanone belongs to the cyclopentanone class of fragrance chemicals, characterized by their five-membered ring structure. The molecule features both ketone and alkyl functional groups that contribute to its complex odor profile. While not found in nature, its structure draws inspiration from naturally occurring musky compounds. Synthesis typically involves cyclization reactions of appropriate precursors, followed by oxidation steps to introduce the oxopropyl moiety. The stereochemistry at the 2-position significantly impacts its olfactory properties.

Physical & Chemical Properties

Perfumer Guide

Note Position
Middle
Volatility
Medium (2-6 hours)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance0.5-2%Up to 5%Used as a subtle modifier
Functional Fragrance0.1-0.5%Up to 1%Limited use due to potency

Classic Accords

Tip: Use sparingly as an enhancer for woody-amber bases, where it adds diffusion and lift.

Alternatives & Comparisons

1
Muscenone CAS 502-72-7

For similar musky-woody effects with better substantivity and lower volatility.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

No specific IFRA restrictions currently apply to this material.

RIFM Assessment

No published RIFM assessment available for this material.

Sustainability

As a synthetic material, 3-(2-Oxopropyl)-2-pentylcyclopentanone offers sustainability advantages by reducing pressure on natural resources. However, its petrochemical origin raises questions about carbon footprint. Future green chemistry approaches may improve its environmental profile through bio-based synthetic routes or enzymatic production methods.

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References

    Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

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    Ingredient Data Sheet

    CAS 40942-73-2

    Physical Properties

    Molecular Weight210.31 g/mol🔬 PubChem
    LogP (Octanol-Water)2.5🔬 PubChem
    Boiling Point262 °C🔬 EPA CompTox
    Vapor Pressure0.0047 mmHg @ 25°C📊 OPERA
    Flash Point117.3 °C🔬 EPA CompTox
    Involatility Index0.0003💻 Calculated
    log Kp (skin permeability)-2.208💻 Calculated
    SMILESCCCCCC1C(CCC1=O)CC(=O)C🔬 PubChem

    Volatility & Performance

    Fragrance NoteHeart💻 Calculated
    Volatility ClassVery slow💻 Calculated
    Persistence Score4.2 / 5💻 Calculated

    Odor & Flavor

    Functional Groupsketone💻 RDKit
    Data Sources & Attribution
    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: DTXSID00866027

    Physical Properties

    Molecular Weight 210.317 g/mol🔬 EPA CompTox
    Density 0.932 g/cm^3📊 OPERA
    Boiling Point 288.344 °C📊 OPERA
    Melting Point 32.784 °C📊 OPERA
    Flash Point 116.198 °C📊 OPERA
    Refractive Index 1.453 Dimensionless📊 OPERA
    Molar Volume 223.504 cm^3/mol📊 OPERA

    Partition & Solubility

    LogP (Octanol-Water) 3.043 Log10 unitless📊 OPERA
    LogD (pH 5.5) 3.043 Log10 unitless📊 OPERA
    LogD (pH 7.4) 3.043 Log10 unitless📊 OPERA
    LogKoa (Octanol-Air) 7.57 Log10 unitless📊 OPERA
    Water Solubility 0.003 mol/L📊 OPERA
    Henry's Law Constant 0 atm-m3/mole📊 OPERA

    Transport Properties

    Vapor Pressure 0.003 mmHg📊 OPERA
    Viscosity 4.762 cP📊 OPERA
    Surface Tension 31.673 dyn/cm📊 OPERA
    Thermal Conductivity 138.231 mW/(m*K)📊 OPERA

    Molecular Descriptors

    Topological Polar Surface Area 34.14 Ų💻 Computed
    H-Bond Donors 0 count💻 Computed
    H-Bond Acceptors 2 count💻 Computed
    Rotatable Bonds 6 count💻 Computed
    Aromatic Rings 0 count💻 Computed
    Molar Refractivity 60.404 cm^3/mol📊 OPERA
    Polarizability 23.946 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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