3,5,6,6-Tetramethyl-4-methyleneheptan-2-one (CAS 81786-75-6) — Woody Middle to base Note Fragrance Ingredient
3,5,6,6-Tetramethyl-4-methyleneheptan-2-one
CAS 81786-75-6
What Is 3,5,6,6-Tetramethyl-4-methyleneheptan-2-one?
3,5,6,6-Tetramethyl-4-methyleneheptan-2-one is a synthetic fragrance ingredient used in modern perfumery. It is found in some niche and avant-garde fragrances. This molecule contributes unique woody and ambery nuances to compositions, often enhancing depth and complexity in modern scent designs.
Safety Profile
USE WITH AWARENESSWhat Does 3,5,6,6-Tetramethyl-4-methyleneheptan-2-one Smell Like?
This synthetic molecule offers a distinctive woody-amber character with subtle green undertones. Initially presenting a crisp, slightly camphoraceous top note, it evolves into a warm, resinous heart with hints of dry wood and faintly sweet nuances. The dry-down reveals a persistent ambery base with a clean, modern edge, making it valuable for contemporary fragrance constructions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a modern woody-amber backbone, providing depth and longevity to this avant-garde green floral composition.
Contributes to the signature woody-musk accord, enhancing the fragrance’s velvety texture and warmth.
Adds a contemporary synthetic wood facet that complements the natural oud notes in this modern classic.
Featured as a solo note to showcase its unique woody-amber character in this minimalist fragrance.
Used subtly to reinforce the woody base and add modernity to the signature sandalwood accord.
2D Molecular Structure
SMILES: CC(C(C)=O)C(=C)C(C)C(C)(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
3,5,6,6-Tetramethyl-4-methyleneheptan-2-one belongs to the ketone class of organic compounds. It features a branched carbon skeleton with a central carbonyl group and multiple methyl substituents, contributing to its woody-amber olfactory profile. The molecule is exclusively synthetic, typically produced through controlled organic synthesis routes involving aldol condensation and subsequent methylation reactions. Its sterically hindered structure contributes to good stability in formulations.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Approx. 220-240 °C (estimated) |
| Density | Approx. 0.89-0.92 g/cm³ (estimated) |
| Solubility | Soluble in alcohol and oils |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | For woody-amber accents |
| Home Fragrance | 0.5-2% | Up to 3% | In diffuser blends |
| Personal Care | 0.1-0.5% | Up to 1% | For subtle woody notes |
| Functional Products | 0.05-0.2% | Up to 0.5% | For masking applications |
Classic Accords
Tip: Use in small quantities to add modern woody depth without overpowering other notes.
Alternatives & Comparisons
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Monitor usage levels as safety data evolves.
GHS Classification
RIFM Assessment
Under review by RIFM. Preliminary data suggests moderate skin sensitization potential at high concentrations.
Sustainability
As a synthetic molecule, this ingredient has minimal environmental impact in production compared to natural alternatives. It requires no agricultural land or endangered resources. The synthesis can be optimized for atom economy and energy efficiency, making it a sustainable choice for modern perfumery when used responsibly.
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References
- IFRA Standards Library (2023). 54th Amendment. IFRA Standards
- Bickers et al. (2011). Safety assessment of fragrance materials. Regulatory Toxicology and Pharmacology. PMID 21524651
- Sell, C. (2006). The Chemistry of Fragrances. RSC Publishing. RSC Chemistry
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 81786-75-6Physical Properties
| Molecular Weight | 182.3 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.8🔬 PubChem |
| Boiling Point | 219 °C🔬 EPA CompTox |
| Vapor Pressure | 1.7378 mmHg @ 25°C📊 OPERA |
| Flash Point | 81.2 °C🔬 EPA CompTox |
| Involatility Index | 0.1387💻 Calculated |
| log Kp (skin permeability) | -1.114💻 Calculated |
| SMILES | CC(C(=O)C)C(=C)C(C)C(C)(C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | balsamicwoody• leffingwell |
| Functional Groups | ketonealkene💻 RDKit |
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: DTXSID8052564
Physical Properties
| Molecular Weight | 182.307 g/mol🔬 EPA CompTox |
| Density | 0.845 g/cm^3📊 OPERA |
| Boiling Point | 219.115 °C📊 OPERA |
| Melting Point | -12.446 °C📊 OPERA |
| Flash Point | 80.149 °C📊 OPERA |
| Refractive Index | 1.434 Dimensionless📊 OPERA |
| Molar Volume | 219.433 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.208 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.208 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.208 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.08 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.657 mmHg📊 OPERA |
| Viscosity | 1.04 cP📊 OPERA |
| Surface Tension | 25.961 dyn/cm📊 OPERA |
| Thermal Conductivity | 117.288 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 | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 57.124 cm^3/mol📊 OPERA |
| Polarizability | 22.646 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.
