4,5-Dimethyl-3-hydroxy-2,5-dihydrofuran-2-one (CAS 28664-35-9) — Sweet Middle Note Fragrance Ingredient
4,5-Dimethyl-3-hydroxy-2,5-dihydrofuran-2-one
CAS 28664-35-9
What Is 4,5-Dimethyl-3-hydroxy-2,5-dihydrofuran-2-one?
4,5-Dimethyl-3-hydroxy-2,5-dihydrofuran-2-one is a synthetic fragrance compound used to create caramel-like, sweet aromas in perfumes and flavored products. You’ll encounter it in gourmand fragrances and some food flavorings. This ingredient matters because it adds depth to sweet compositions, mimicking natural caramelization processes without relying on actual food extracts.
Safety Profile
USE WITH AWARENESSWhat Does 4,5-Dimethyl-3-hydroxy-2,5-dihydrofuran-2-one Smell Like?
This lactone delivers an intense caramelized sugar aroma with burnt sugar nuances. The top note presents as rich maple syrup, evolving into a heart of brown butter and toasted hazelnuts. Dry-down reveals a persistent, slightly smoky sweetness reminiscent of crème brûlée. The character remains linear but gains subtle woody undertones over time.
2D Molecular Structure
SMILES: CC1OC(=O)C(O)=C1C
Chemistry, Properties & Perfumer Guide
The Chemistry
This γ-lactone belongs to the furanone class, structurally related to sotolone. While found in trace amounts in some roasted foods, commercial production involves synthetic routes including cyclization of appropriate hydroxy acids. The molecule’s stereochemistry influences its odor profile, with different enantiomers exhibiting varying intensity.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Molecular Weight | 142.15 g/mol |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Gourmand accords |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Masking agent |
| Flavorings | 10-50 ppm | Up to 100 ppm | Caramel notes |
Classic Accords
Tip: Use with vanillic materials to enhance sweetness without becoming cloying.
Alternatives & Comparisons
More intense curry-like character at lower thresholds, suitable when seeking spicier caramel nuances.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific IFRA restrictions. General lactone guidelines apply.
RIFM Assessment
Currently under review by RIFM. Preliminary data suggests moderate safety profile.
Sustainability
Synthetic production avoids agricultural land use. Manufacturing requires controlled conditions but generates minimal waste. Not biodegradable, but used at very low levels that pose negligible environmental impact.
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References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press.
- Leffingwell & Associates (2021). Lactones in Perfumery.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 28664-35-9Physical Properties
| Molecular Weight | 128.13 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 0.4🔬 PubChem |
| Boiling Point | 93 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -3.198💻 Calculated |
| SMILES | CC1C(=C(C(=O)O1)O)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
Odor & Flavor
| Primary Descriptors | caramel• leffingwell |
| Functional Groups | esteretheralkene💻 RDKit |
Sensory Thresholds
| Odor Detection Threshold | 0.0062 ppm (n=11)📖 van Gemert |
Trade Names
| Macrolide® (Symrise), Exaltolide®, Exaltolide®Total (Fir-📖 Surburg |
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: DTXSID4047674
Physical Properties
| Molecular Weight | 128.127 g/mol🔬 EPA CompTox |
| Density | 1.153 g/cm^3📊 OPERA |
| Boiling Point | 239.325 °C📊 OPERA |
| Melting Point | 27 °C🔬 EPA CTX |
| Flash Point | 116.384 °C📊 OPERA |
| Refractive Index | 1.44 Dimensionless📊 OPERA |
| Molar Volume | 112.738 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 0.312 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 0.312 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 0.312 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.31 Log10 unitless📊 OPERA |
| Water Solubility | 0.489 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.023 mmHg📊 OPERA |
| Viscosity | 9.997 cP📊 OPERA |
| Surface Tension | 31.591 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 46.53 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 3 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 29.729 cm^3/mol📊 OPERA |
| Polarizability | 11.786 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.
