3-Methyl-2-butenyl acetate (CAS 1191-16-8) — Green Top Note Fragrance Ingredient
3-Methyl-2-butenyl acetate
CAS 1191-16-8
What Is 3-Methyl-2-butenyl acetate?
3-Methyl-2-butenyl acetate is a fruity, green-smelling synthetic compound used in perfumes to create fresh, apple-like top notes. You’ll find it in many fruity floral fragrances and body care products. This ingredient matters because it adds a crisp, natural fruitiness without being cloying, bridging floral and citrus notes seamlessly in modern perfumery.
Safety Profile
GENERALLY SAFEWhat Does 3-Methyl-2-butenyl acetate Smell Like?
A vibrant burst of green apple peel and unripe banana gives way to a heart of dewy rose stems and freshly cut grass. The dry-down reveals a whisper of sweet pear skin and a clean musk reminiscent of sun-warmed cotton. Surprisingly long-lasting for a top note, it maintains a crisp freshness without turning sharp, like biting into a just-picked Granny Smith apple at dawn.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the natural crispness of violet leaf, creating that iconic ‘just-rained-on lawn’ effect. The acetate’s green apple facets make the citrus opening feel more dimensional.
Provides the juicy, biting freshness that makes the lemon note pop. Works with bamboo to create that ‘icy citrus’ illusion in this summer staple.
2D Molecular Structure
SMILES: CC(C)=CCOC(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
An ester formed from prenol (3-methyl-2-buten-1-ol) and acetic acid, this molecule belongs to the family of unsaturated acetates that contribute fresh top notes. Industrially synthesized via Fischer esterification, its structure allows for both fruity and green olfactory characteristics. The branched chain enhances volatility while the double bond contributes to its fresh-cut quality.
Physical & Chemical Properties
| Appearance | Colorless liquid |
|---|---|
| Boiling Point | ~175-180 °C (estimated) |
| Density | ~0.89 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | For fresh green accents |
| Body Care | 0.5-1.5% | Up to 2% | Adds fruity freshness to shower gels |
Classic Accords
Tip: Use with citrus oils to prevent them from turning waxy in the dry-down.
Alternatives & Comparisons
More straightforward pear/apple character without the green nuances. Use when you need simpler fruity top notes.
Similar structure but with more pronounced banana and tropical fruit aspects. Better for exotic compositions.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted under current IFRA standards (Amendment 49).
RIFM Assessment
Considered safe for current fragrance use based on RIFM evaluation.
Sustainability
As a synthetic material, production avoids agricultural land use. Typical synthesis routes from petrochemical feedstocks, though bio-based production methods are being explored. More sustainable than some natural fruit extracts which require large quantities of plant material.
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References
- Bauer, K. et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH. ISBN 9783527618421
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 1191-16-8Physical Properties
| Molecular Weight | 128.17 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 151 °C🔬 EPA CompTox |
| Vapor Pressure | 1.9502 mmHg @ 25°C📊 OPERA |
| Flash Point | 45 °C🔬 EPA CompTox |
| Involatility Index | 0.1857💻 Calculated |
| log Kp (skin permeability) | -2.204💻 Calculated |
| SMILES | CC(=CCOC(=O)C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | applebananafruitygreen• leffingwell |
| Functional Groups | esteretheralkene💻 RDKit |
| “Fresh and very diffusive, fruity, Banana-like and Bergamot-like odor of poor tenacity.”📖 Arctander | |
Flavor Notes (Arctander)
| “Powerful, fruity and sweet, Pear-Banana-like taste at 10 ppm or lower. This material was made commercially available in 1966 at a time when Lavandin oil was scarce and expensive. Any material that could help improve an artificial Lavandin or Lavender was of immediate interest. beyond Lavandin, Laven”📖 Arctander |
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: DTXSID9047128
Physical Properties
| Molecular Weight | 128.171 g/mol🔬 EPA CompTox |
| Density | 0.92 g/cm^3🔬 EPA CTX |
| Boiling Point | 149.25 °C🔬 EPA CTX |
| Melting Point | -48.427 °C📊 OPERA |
| Flash Point | 45.667 °C🔬 EPA CTX |
| Refractive Index | 1.426 Dimensionless📊 OPERA |
| Molar Volume | 140.981 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.938 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.938 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.62 Log10 unitless📊 OPERA |
| Water Solubility | 0.034 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 2.363 mmHg🔬 EPA CTX |
| Viscosity | 0.749 cP📊 OPERA |
| Surface Tension | 25.329 dyn/cm📊 OPERA |
| Thermal Conductivity | 133.895 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 36.154 cm^3/mol📊 OPERA |
| Polarizability | 14.333 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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