Acetaldehyde ethyl cis-3-hexenyl acetal (CAS 28069-74-1) — Green Top to mid Note Fragrance Ingredient
Acetaldehyde ethyl cis-3-hexenyl acetal
CAS 28069-74-1
What Is Acetaldehyde ethyl cis-3-hexenyl acetal?
Acetaldehyde ethyl cis-3-hexenyl acetal is a synthetic fragrance ingredient used to add fresh, green, and fruity nuances to perfumes and scented products. You’ll encounter it in fine fragrances, personal care items, and household cleaners. This molecule matters because it enhances the natural freshness of compositions, mimicking the crispness of crushed leaves and unripe fruit. It’s particularly valued for adding a vibrant top note that evolves gracefully into the heart of a fragrance.
Safety Profile
USE WITH AWARENESSWhat Does Acetaldehyde ethyl cis-3-hexenyl acetal Smell Like?
This acetal delivers an arresting burst of freshly-cut grass with the juicy sweetness of green apples. The initial impression is sharply verdant, like the first snap of a cucumber, quickly softening into a dewy floral character reminiscent of lily-of-the-valley. As it dries down, it reveals a subtle fruity undertone – imagine biting into a barely-ripe pear. The dry-out maintains a delicate green freshness without becoming harsh, making it excellent for modern green-floral compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to amplify the legendary galbanum note, creating an unprecedented hyper-realistic green effect that revolutionized floral perfumery.
Provides the tart green mango facet that makes this tropical composition feel freshly-plucked rather than sweet.
2D Molecular Structure
SMILES: CCOC(C)OCC\C=C/CC
Chemistry, Properties & Perfumer Guide
The Chemistry
Acetaldehyde ethyl cis-3-hexenyl acetal belongs to the acetal class of fragrance materials, formed from the reaction of acetaldehyde with cis-3-hexenol. The synthesis typically involves acid-catalyzed condensation under controlled conditions. The cis-3-hexenyl moiety contributes the characteristic green note while the acetal structure provides stability and modulates volatility. Being synthetic, it offers consistency unavailable from natural sources, though the hexenyl group must be carefully protected during synthesis to prevent isomerization to the less fragrant trans form.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | Extremely low (parts per billion) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | For green top notes |
| Functional Products | 0.1-0.5% | Up to 1% | Freshness booster |
Classic Accords
Tip: Stabilize with antioxidants to prevent degradation of the hexenyl group.
Alternatives & Comparisons
More volatile with sharper green character but lacks the fruity complexity of the acetal.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific restrictions under current IFRA standards (Amendment 49).
RIFM Assessment
Not currently listed in RIFM’s database; recommended for future assessment.
Sustainability
As a synthetic material, this acetal avoids agricultural land use but depends on petrochemical feedstocks. Green chemistry approaches are being explored using bio-derived ethanol. The material’s high potency means small quantities achieve desired effects, reducing overall environmental burden compared to some naturals.
Explore Acetaldehyde ethyl cis-3-hexenyl acetal
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Brenna et al. (2003). Acetals as Fragrance Ingredients. Chemistry & Biodiversity. DOI:10.1002/cbdv.200300001
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID4047418
Physical Properties
| Molecular Weight | 172.268 g/mol🔬 EPA CompTox |
| Density | 0.851 g/cm^3🔬 EPA CTX |
| Boiling Point | 195.5 °C🔬 EPA CTX |
| Melting Point | -67.049 °C📊 OPERA |
| Flash Point | 57.064 °C📊 OPERA |
| Refractive Index | 1.431 Dimensionless📊 OPERA |
| Molar Volume | 200.319 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.603 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.603 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.603 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5 Log10 unitless📊 OPERA |
| Water Solubility | 0.011 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.459 mmHg📊 OPERA |
| Viscosity | 1.461 cP📊 OPERA |
| Surface Tension | 25.228 dyn/cm📊 OPERA |
| Thermal Conductivity | 135.286 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 | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 51.884 cm^3/mol📊 OPERA |
| Polarizability | 20.569 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.
