Citral diethyl acetal (CAS 7492-66-2) — Citrus Top to mid Note Fragrance Ingredient
Citral diethyl acetal
CAS 7492-66-2
What Is Citral diethyl acetal?
Citral diethyl acetal is a synthetic fragrance ingredient used to create fresh, citrusy, and slightly floral notes in perfumes and scented products. You’ll encounter it in citrus colognes, household cleaners, and air fresheners. This compound matters because it provides a more stable and longer-lasting citrus character than natural citral, making scents more durable in various formulations.
Safety Profile
GENERALLY SAFEWhat Does Citral diethyl acetal Smell Like?
Citral diethyl acetal bursts with a vibrant, lemony-citrus top note that’s brighter and more candied than natural citral. The initial sharpness quickly mellows into a smooth, slightly herbal heart with whispers of lime peel and verbena. As it dries down, it reveals a subtle floral undertone reminiscent of neroli, making it more complex than basic citrus notes. Unlike citral, it lacks the harsh, metallic edge, instead offering a rounded, almost juicy quality that lingers like the memory of fresh lemon zest.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to amplify the citrus-floral duality, creating a sparkling lemon-bergamot opening that transitions seamlessly into the jasmine heart.
Provides the bright, sun-kissed lemon top note that distinguishes this Mediterranean-inspired fragrance.
Contributes to the fresh, unisex citrus accord that makes this fragrance universally appealing.
Used sparingly to enhance the natural citrus oils, adding modernity to this classic cologne structure.
Helps create the watery, transparent citrus effect that defines this aquatic floral fragrance.
2D Molecular Structure
SMILES: CCOC(OCC)C=C(C)CCC=C(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Citral diethyl acetal is an acetal derivative of citral (a mixture of geranial and neral). It’s synthesized through acid-catalyzed reaction of citral with ethanol, forming a more stable compound than the aldehyde precursor. This modification protects the reactive aldehyde group, improving shelf life while maintaining citrus character. The acetal form is less prone to oxidation and polymerization, making it particularly valuable in alkaline formulations like soaps and detergents where citral would normally degrade quickly.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Approx. 230 °C |
| Density | ~0.88 g/cm³ |
| Refractive Index | ~1.45 |
| Solubility | Soluble in alcohol, oils; insoluble in water |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 10% | For citrus-floral accords |
| Functional Products | 0.1-0.5% | Up to 1% | Soaps and detergents |
| Household Cleaners | 0.05-0.2% | Up to 0.5% | For fresh lemon notes |
| Candles | 0.5-2% | Up to 3% | Bright top note |
Classic Accords
Tip: Use to fix citrus top notes in alkaline formulations where citral would normally degrade.
Alternatives & Comparisons
For a more raw, intense lemon note when stability isn’t a concern.
When a more diffusive, nitrile-type lemon character is desired.
For a fresh, green citrus effect with better tenacity.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Included in the IFRA Transparency List.
GHS Classification
RIFM Assessment
Evaluated by RIFM and considered safe for use at current industry levels.
Sustainability
As a synthetic material, citral diethyl acetal reduces pressure on natural citrus oil production. Its production from citral (often derived from lemongrass oil) does require agricultural inputs, but the acetal form’s stability means less product waste compared to unstable natural citrus ingredients. Current synthesis routes are being optimized for greener chemistry approaches.
Explore Citral diethyl acetal
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
- Arctander, S. (1969). Perfume and Flavor Chemicals. Allured Publishing.
- IFRA Standards Library Link
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 7492-66-2Physical Properties
| Molecular Weight | 226.35 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 4.2🔬 PubChem |
| Boiling Point | 230 °C🔬 EPA CompTox |
| Vapor Pressure | 19.1 mmHg @ 25°C📊 OPERA |
| Flash Point | 79 °C🔬 EPA CompTox |
| Involatility Index | 1.3683💻 Calculated |
| log Kp (skin permeability) | -1.099💻 Calculated |
| SMILES | CCOC(C=C(C)CCC=C(C)C)OCC🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Fast💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | citrusfreshgreen• leffingwell |
| Functional Groups | etheralkene💻 RDKit |
| “Mild and fresh, green-citrusy, almost veg- etable-juicy odor with a pleasant, natural oily-fruity undertone. The odor is very heavily influenced by the presence of small amounts of Citral. Perhaps partly because acetals were not produced in a very pure state when they first appeared on the market, it has been more or less conventional that the odor of Citral diethylacetal has been described with phrases including those used for Citral.”📖 Arctander | |
| Citral diethyl acetal has a mild, green, citrus odor and a green, oily, citrus-peel flavor.📖 Fenaroli | |
Flavor Notes (Arctander)
| “miscible with most perfume and flavor oils. Used in flavor compositions, mainly in Citrus flavors along with natural oils and”📖 Arctander |
Regulatory Status
| FEMA Number | FEMA 2304⚖️ FEMA GRAS |
| GRAS Status | Generally Recognized as Safe⚖️ FEMA GRAS |
| IOFI Classification | Artificial📖 Fenaroli |
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: DTXSID1024837
Physical Properties
| Molecular Weight | 226.36 g/mol🔬 EPA CompTox |
| Density | 0.871 g/cm^3🔬 EPA CTX |
| Boiling Point | 230 °C🔬 EPA CTX |
| Melting Point | -54.292 °C📊 OPERA |
| Flash Point | 79 °C🔬 EPA CTX |
| Refractive Index | 1.453 Dimensionless📊 OPERA |
| Molar Volume | 259.563 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.627 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.627 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.627 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.77 Log10 unitless📊 OPERA |
| Water Solubility | 0.004 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 30.7 mmHg🔬 EPA CTX |
| Viscosity | 2.54 cP📊 OPERA |
| Surface Tension | 25.96 dyn/cm📊 OPERA |
| Thermal Conductivity | 134.337 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 18.46 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 8 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 70.159 cm^3/mol📊 OPERA |
| Polarizability | 27.813 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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