Undecanal (CAS 112-44-7) — Citrus Top Note Fragrance Ingredient
Undecanal
CAS 112-44-7
What Is Undecanal?
Undecanal is a synthetic fragrance ingredient with a bright, citrusy aroma reminiscent of freshly peeled orange zest. You’ll encounter it in citrus-forward perfumes, cleaning products, and some fruity body care items. This aldehyde matters because it provides the crisp ‘sparkle’ in many fresh fragrances, adding lift to citrus blends without the fleeting nature of real citrus oils.
Safety Profile
GENERALLY SAFE
What Does Undecanal Smell Like?
Undecanal bursts with the exhilarating zest of just-squeezed tangerines, carrying a slightly waxy, aldehydic edge that distinguishes it from natural citrus oils. The opening is all effervescent citrus peel—think mandarin segments bursting with juice—before settling into a clean, soapy quality reminiscent of luxury hotel hand soaps. Unlike fleeting citrus top notes, undecanal lingers for hours, transforming gradually into a soft, slightly floral muskiness that provides surprising tenacity for an aldehyde.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Undecanal provides the luminous citrus sparkle in this classic, blending with lemon and rosemary to create one of perfumery’s most iconic fresh openings.
Used here to amplify the bergamot top note, undecanal adds a contemporary metallic edge to this unisex citrus-woody accord.
Undecanal’s crispness cuts through the apple note, creating the sensation of biting into a chilled Sicilian lemon on a hot day.
2D Molecular Structure
SMILES: CCCCCCCCCCC=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Undecanal is a straight-chain fatty aldehyde (C11H22O) belonging to the same family as the classic Chanel No. 5 aldehydes. Unlike its shorter-chain cousins, undecanal’s longer carbon chain provides greater stability and tenacity. Industrially synthesized via oxidation of undecanol or hydroformylation of 1-decene, this molecule showcases how small structural changes dramatically alter odor properties—compare to decanal’s orange blossom character versus undecanal’s pure citrus.
Physical & Chemical Properties
| Boiling Point | 222-223 °C |
|---|---|
| Density | 0.825 g/cm³ |
| Flash Point | 93 °C |
| Refractive Index | 1.428-1.432 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Citrus enhancer |
| Functional Products | 0.1-0.5% | Up to 1% | Freshness booster |
Classic Accords
+ Galbanum + Violet Leaf = Futuristic green
+ Vanillin + Musk = Orange creamsicle
Tip: Use undecanal to extend citrus top notes—it bridges the gap between fleeting citrus oils and heart notes.
Alternatives & Comparisons
More orange blossom than citrus, use when a sweeter, floral-citrus character is desired at similar tenacity.
For sharper lemon-lime character, though citral is more restricted and less stable in formulations.
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
No restrictions under IFRA 51st Amendment.
RIFM Assessment
RIFM assessment confirms safe use at current industry levels.
Sustainability
As a petrochemical derivative, undecanal’s environmental impact stems from fossil fuel feedstocks. However, its high odor potency means minimal quantities are needed compared to natural citrus oils, which require vast agricultural resources. Emerging bio-based routes using fermented sugars may offer greener production methods in the future.
Explore Undecanal
Browse essential oils and aroma compounds.
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Industry & Science Data
References
- Burdock, G. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090869
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Physicochemical Properties
DTXSID: DTXSID4021688
Physical Properties
| Molecular Weight | 170.296 g/mol🔬 EPA CompTox |
| Density | 0.829 g/cm^3🔬 EPA CTX |
| Boiling Point | 225 °C🔬 EPA CTX |
| Melting Point | -3.091 °C🔬 EPA CTX |
| Flash Point | 97.69 °C🔬 EPA CTX |
| Refractive Index | 1.426 Dimensionless📊 OPERA |
| Molar Volume | 207.428 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3452.92 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 4.384 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.384 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.77 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.364 mmHg🔬 EPA CTX |
| Viscosity | 2.201 cP📊 OPERA |
| Surface Tension | 28.357 dyn/cm📊 OPERA |
| Thermal Conductivity | 145.616 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 | 9 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 53.197 cm^3/mol📊 OPERA |
| Polarizability | 21.089 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.
