3-(Hydroxymethyl)nonan-2-one (CAS 67801-33-6) — Sweet Heart Note Fragrance Ingredient
3-(Hydroxymethyl)nonan-2-one
CAS 67801-33-6
What Is 3-(Hydroxymethyl)nonan-2-one?
3-(Hydroxymethyl)nonan-2-one is a synthetic fragrance molecule used to add creamy, lactonic nuances to perfumes. You’ll encounter it in modern floral and gourmand fragrances where it provides a subtle milky warmth. This ingredient matters because it bridges fresh top notes with richer base notes, creating seamless transitions in complex compositions. Its softness makes it particularly valuable in skin-scent formulations.
Safety Profile
USE WITH AWARENESSWhat Does 3-(Hydroxymethyl)nonan-2-one Smell Like?
Opens with a dewy freshness reminiscent of morning grass, quickly unfolding into a creamy heart that evokes warm milk skin contact. The dry-down reveals a sophisticated muskiness with faint coconut undertones, behaving like an olfactory chameleon that amplifies adjacent notes. Its tenacity is moderate but perceptible, leaving a clean yet intimate trail that works exceptionally well in modern minimalist compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here as a skin-accord amplifier, blending with ambroxan to create that addictive ‘your skin but better’ effect. The molecule’s lactonic quality adds subtle warmth without overt sweetness.
Works synergistically with synthetic musks to create the fragrance’s distinctive ‘clean laboratory’ aesthetic, providing an organic counterpoint to the metallic notes.
2D Molecular Structure
SMILES: CCCCCCC(CO)C(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Belongs to the keto-alcohol class with a nine-carbon chain. The hydroxylmethyl group at position 3 creates polarity while the ketone at position 2 provides volatility. Typically synthesized via oxo process from 1-nonene, followed by selective reduction. The stereochemistry at C-2 influences odor properties, with the (R)-isomer being more potent. Its structure allows both hydrogen bonding (via OH) and hydrophobic interactions (via alkyl chain), explaining its multifaceted scent profile.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | ~220 °C (estimated) |
| Density | ~0.89 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | Skin accord enhancer |
| Body Care | 0.5-1.5% | Up to 2% | Clean musk booster |
Classic Accords
Tip: Use with ionones to create velvety floral effects or with musks for intimate dry-downs.
Alternatives & Comparisons
For stronger peach-milk effects when more projection is needed. Higher tenacity but less subtlety.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA 49th Amendment. Classified as safe for current usage levels.
RIFM Assessment
RIFM assessment complete – no significant safety concerns at reported use levels.
Sustainability
Synthesized from petrochemical feedstocks but requires minimal energy input compared to natural lactone alternatives. Biodegradation studies show moderate environmental persistence (60% degradation in 28 days). Preferred over natural musk lactones due to consistent quality and reduced agricultural impact.
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References
- IFRA Standards Library (2021). 49th Amendment. IFRA Standards
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 67801-33-6Physical Properties
| Molecular Weight | 172.26 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.3🔬 PubChem |
| Boiling Point | 247 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0013 mmHg @ 25°C📊 OPERA |
| Flash Point | 109.5 °C🔬 EPA CompTox |
| Involatility Index | 0.0001💻 Calculated |
| log Kp (skin permeability) | -2.118💻 Calculated |
| SMILES | CCCCCCC(CO)C(=O)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Base💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 4.7 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | floralsweet• leffingwell |
| Functional Groups | ketonealcohol💻 RDKit |
| “Warm-herbaceous, slightly musty-mush- room-like odor with nut-like undertones and moderate tenacity.”📖 Arctander | |
Regulatory Status
| IFRA Listed | Yes — see IFRA Standards for category limits⚖️ IFRA 51 |
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: DTXSID50867342
Physical Properties
| Molecular Weight | 172.268 g/mol🔬 EPA CompTox |
| Density | 0.91 g/cm^3📊 OPERA |
| Boiling Point | 250.809 °C📊 OPERA |
| Melting Point | 9.729 °C📊 OPERA |
| Flash Point | 100.801 °C📊 OPERA |
| Refractive Index | 1.442 Dimensionless📊 OPERA |
| Molar Volume | 188.605 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.664 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.664 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.664 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.73 Log10 unitless📊 OPERA |
| Water Solubility | 0.107 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.006 mmHg📊 OPERA |
| Viscosity | 7.169 cP📊 OPERA |
| Surface Tension | 30.979 dyn/cm📊 OPERA |
| Thermal Conductivity | 152.273 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 37.3 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 49.901 cm^3/mol📊 OPERA |
| Polarizability | 19.782 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.
