3-Octen-2-one (CAS 1669-44-9) — Green Middle Note Fragrance Ingredient

ByThe Good Scents
Green · Woody

3-Octen-2-one

CAS 1669-44-9

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

What Is 3-Octen-2-one?

3-Octen-2-one is a synthetic fragrance ingredient that adds a mushroom-like, earthy character to perfumes. You’ll encounter it in niche fragrances aiming for naturalistic forest or truffle effects. This ketone matters because it provides an authentic damp woodland note that’s difficult to achieve with other materials, bridging the gap between floral and woody accords.

Safety Profile

USE WITH AWARENESS
Generally safeUse with awarenessProfessional use
✓ IFRA compliant at typical usage levels
⚠ Skin sensitization potential
CAS
1669-44-9
Formula
Mixture
MW
Variable
Odor Family
Green · Woody
Layer 1 · Enthusiast

What Does 3-Octen-2-one Smell Like?

3-Octen-2-one delivers an intensely earthy, fungal aroma reminiscent of freshly turned forest soil and porcini mushrooms. The initial burst is pungent and slightly metallic, evolving into a damp leaf litter character with time. In dry-down, it lingers as a subtle woody-musty note that blends beautifully with oakmoss and vetiver. When diluted, it can suggest the humid air after autumn rain or the scent of truffles shaved over pasta.

Scent Profile

In Famous Fragrances

Fragrance associations may not reflect actual formulations.

Chêne(Serge Lutens, 2004)

Used here to create the damp oak bark effect, enhancing the woody core with fungal complexity.

Truffe(Byredo, 2015)

Provides the authentic truffle accord that forms the gourmand-woody heart of this unusual fragrance.

Layer 2

2D Molecular Structure

3-Octen-2-one

SMILES: CCCCC=CC(C)=O

Chemistry, Properties & Perfumer Guide

The Chemistry

3-Octen-2-one is an unsaturated ketone with an eight-carbon chain. Industrially synthesized via oxidation of corresponding alcohols or controlled pyrolysis of fatty acids. The molecule’s reactivity comes from its conjugated double bond system and ketone functionality. No chiral centers present. Key synthetic routes involve catalytic dehydrogenation of 3-octanol or controlled oxidation of 3-octen-2-ol using manganese dioxide.

Physical & Chemical Properties

Boiling Point~190 °C (estimated)
Density~0.85 g/cm³ (estimated)

Perfumer Guide

Note Position
Middle
Volatility
Moderate (2-4 hours)
Blending
Good with woody notes
ApplicationTypical %RangeNotes
Fine Fragrance0.1-0.5%Up to 1%Used sparingly for earthy effects
Functional0.01-0.1%Up to 0.3%Masking agent for industrial products

Classic Accords

Tip: Use below 0.5% to avoid overwhelming compositions with fungal notes.

Alternatives & Comparisons

1
Geosmin CAS 19700-21-1

More intense earthy note but less mushroom-like. Use when needing pure soil character without fungal aspects.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

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

IFRA Status

No specific restrictions under current IFRA standards (Amendment 49).

GHS Classification

H315 Skin irritation

RIFM Assessment

RIFM evaluation confirms safe use at current industry levels.

Sustainability

Synthetic production avoids wild harvesting of mushrooms. Manufacturing typically uses petrochemical feedstocks, though bio-based routes are being explored. Low environmental persistence due to moderate biodegradability.

Explore 3-Octen-2-one

Browse essential oils and aroma compounds.

Browse on iHerb →

Affiliate disclosure: we may earn a small commission at no extra cost to you.

References

  1. Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090866

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

Report a data error

Ingredient Data Sheet

CAS 1669-44-9

Physical Properties

Molecular Weight126.2 g/mol🔬 PubChem
LogP (Octanol-Water)2.3🔬 PubChem
Boiling Point100 °C🔬 EPA CompTox
log Kp (skin permeability)-1.837💻 Calculated
SMILESCCCCC=CC(=O)C🔬 PubChem

Volatility & Performance

Fragrance NoteTop💻 Calculated

Odor & Flavor

Primary Descriptorsearthyfruitymushroom• leffingwell
Functional Groupsketonealkene💻 RDKit
“It is also used sparingly in Citrus colognes, Sweet Pea, Oriental bases, Rose variations, New Mown Hay, and in general as part of powerful green-floral topnote complexes. It is generally agreed that the above mentioned impurity is largely responsible for the "grassy" odor in the commercial product. Pure Methylheptenone is available and has, indeed, a less fatty-grassy odor.”📖 Arctander
3-Octen-2-one has a fruity, lemon odor.📖 Fenaroli

Flavor Notes (Arctander)

“In extreme dilution (below 5 ppm) it has a fruity, green-Banana-like or unripe Berry-like taste. Higher dilutions produce harsh and pungent notes. The ketone is used in flavor compositions in minute traces, primarily in imitation Apple, Banana, Citrus, Date, Blackcurrant, Mulberry, Raspberry, Melon,”📖 Arctander

Sensory Thresholds

Odor Detection Threshold0.0322 ppm (n=3)📖 van Gemert

Regulatory Status

IFRA ListedYes — see IFRA Standards for category limits⚖️ IFRA 51
FEMA NumberFEMA 2707⚖️ FEMA GRAS
GRAS StatusGenerally Recognized as Safe⚖️ FEMA GRAS
IOFI ClassificationNature Identical📖 Fenaroli
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: DTXSID1061867

Physical Properties

Molecular Weight 126.199 g/mol🔬 EPA CompTox
Density 0.853 g/cm^3🔬 EPA CTX
Boiling Point 177.516 °C📊 OPERA
Melting Point -26.768 °C📊 OPERA
Flash Point 62.084 °C📊 OPERA
Refractive Index 1.431 Dimensionless📊 OPERA
Molar Volume 151.324 cm^3/mol📊 OPERA

Partition & Solubility

LogP (Octanol-Water) 2.108 Log10 unitless📊 OPERA
LogD (pH 5.5) 2.108 Log10 unitless📊 OPERA
LogD (pH 7.4) 2.108 Log10 unitless📊 OPERA
LogKoa (Octanol-Air) 4.52 Log10 unitless📊 OPERA
Water Solubility 0.018 mol/L📊 OPERA
Henry's Law Constant 0 atm-m3/mole📊 OPERA

Transport Properties

Vapor Pressure 0.764 mmHg📊 OPERA
Surface Tension 27.944 dyn/cm📊 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 39.199 cm^3/mol📊 OPERA
Polarizability 15.54 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.

Similar Posts