Methyl heptenone (CAS 110-93-0) — Green Top Note Fragrance Ingredient
Methyl heptenone
CAS 110-93-0
What Is Methyl heptenone?
Methyl heptenone is a synthetic green note used in perfumery to create fresh, leafy aromas. You’ll encounter it in citrus colognes, herbaceous fragrances, and some floral compositions. This molecule matters because it adds an authentic ‘just-crushed’ plant stem quality that natural materials can’t always deliver consistently. It’s the secret behind many perfumes that smell like dewy morning gardens or freshly picked herbs.
Safety Profile
GENERALLY SAFEWhat Does Methyl heptenone Smell Like?
Methyl heptenone bursts with a sharp, green intensity reminiscent of snapping a celery stalk or crushing tomato leaves. The opening is aggressively vegetal – like chlorophyll concentrate with a metallic edge. As it settles, the harshness mellows into a sophisticated green tea nuance with faint citrus undertones. In drydown, it leaves a clean, slightly waxy impression akin to the white membrane inside citrus peels. Unlike some green notes that turn sweet, this maintains a dry, almost bitter character throughout its evolution.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Provides the crisp green backbone that makes the citrus sparkle, creating the illusion of freshly crushed lemon leaves alongside bergamot.
Used to amplify the mojito accord, giving the lime and mint combination an authentic crushed-stem realism.
Contributes to the startling green mango effect, making the fruit note smell freshly plucked with sap still on the stem.
2D Molecular Structure
SMILES: CC(C)=CCCC(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Methyl heptenone is a methylated enone, specifically 6-methyl-5-hepten-2-one. As a synthetic molecule, it’s produced via aldol condensation of isovaleraldehyde with acetone, followed by dehydration. The resulting α,β-unsaturated ketone structure is responsible for its potent green character. While not found abundantly in nature, traces occur in some essential oils like lemongrass. The double bond at the 5-position creates reactivity that perfumers exploit for complex transformations in fragrance blends.
Physical & Chemical Properties
| Boiling Point | 173-175 °C |
|---|---|
| Density | 0.85 g/cm³ |
| Refractive Index | 1.438 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Green accent note |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Freshness booster |
Classic Accords
Tip: Use with citrus oils to prevent excessive sweetness and add botanical realism.
Alternatives & Comparisons
When a more floral-green effect is needed without the harshness, this gives similar vegetative character with better blending.
For a greener, grassier effect without the ketonic sharpness, though it lacks the tenacity of methyl heptenone.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH, EU Cosmetics Regulation standards update periodically. Consult current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
Not restricted under current IFRA standards (as of 49th Amendment).
RIFM Assessment
RIFM evaluation confirms safe use at current industry levels with no significant sensitization potential.
Sustainability
As a synthetic material, methyl heptenone has consistent production with minimal batch variation. The synthesis route from basic petrochemical feedstocks makes it more sustainable than some natural green materials that require large-scale plant harvesting. No known ecological toxicity concerns at usage levels.
Explore Methyl heptenone
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781439847503
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID5021629
Physical Properties
| Molecular Weight | 126.199 g/mol🔬 EPA CompTox |
| Density | 0.85 g/cm^3🔬 EPA CTX |
| Boiling Point | 172.947 °C🔬 EPA CTX |
| Melting Point | -67.05 °C🔬 EPA CTX |
| Flash Point | 52.46 °C🔬 EPA CTX |
| Refractive Index | 1.43 Dimensionless📊 OPERA |
| Molar Volume | 151.125 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.09 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.281 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.281 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.5 Log10 unitless📊 OPERA |
| Water Solubility | 0.024 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.874 mmHg🔬 EPA CTX |
| Viscosity | 0.763 cP📊 OPERA |
| Surface Tension | 25.58 dyn/cm📊 OPERA |
| Thermal Conductivity | 134.592 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 | 39.042 cm^3/mol📊 OPERA |
| Polarizability | 15.477 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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