1-Cyclohexene-1-carboxaldehyde, 4-ethenyl- (CAS 1049017-68-6) — Green Top to Middle Note Fragrance Ingredient
1-Cyclohexene-1-carboxaldehyde, 4-ethenyl-
CAS 1049017-68-6
What Is 1-Cyclohexene-1-carboxaldehyde, 4-ethenyl-?
1-Cyclohexene-1-carboxaldehyde, 4-ethenyl- is a synthetic fragrance ingredient used in modern perfumery. While not commonly recognized by name, it contributes to contemporary scent profiles in niche and avant-garde fragrances. This molecule is valued for its unique structural properties that allow perfumers to create novel olfactory effects not found in nature, making it a tool for pushing creative boundaries in fragrance design.
Safety Profile
USE WITH AWARENESSWhat Does 1-Cyclohexene-1-carboxaldehyde, 4-ethenyl- Smell Like?
This synthetic aldehyde presents a complex olfactory profile that evolves dramatically from first application. The initial burst carries metallic-green undertones with a surprising fruity-floral lift reminiscent of underripe starfruit crossed with magnolia petals. As it develops, a camphoraceous coolness emerges, balanced by subtle woody-ambery facets. The dry-down reveals a clean, slightly musky character with lingering citrus-herbal echoes. The overall effect is modern, slightly futuristic, with excellent diffusion properties that make it useful for creating expansive top-to-middle note transitions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a primary building block to create an abstract, futuristic floralcy that challenges traditional scent expectations. The aldehyde’s green-metallic facets are amplified to create a scent that feels both familiar and completely novel.
Employed in the heart accord to bridge synthetic ambery notes with natural citrus elements, creating a seamless transition that maintains brightness throughout wear.
Used sparingly to enhance the green, almost electric quality of the vanilla-rhubarb core, adding dimensionality to what would otherwise be a straightforward gourmand.
Forms part of the ‘hyper-realistic’ green accord, contributing camphoraceous lift and persistence to what would otherwise be fleeting natural green notes.
2D Molecular Structure
SMILES: C=CC1CCC(C=O)=CC1
Chemistry, Properties & Perfumer Guide
The Chemistry
1-Cyclohexene-1-carboxaldehyde, 4-ethenyl- belongs to the class of cyclic unsaturated aldehydes, characterized by their reactive carbonyl group conjugated with a carbon-carbon double bond in a six-membered ring. The vinyl substituent at position 4 introduces additional reactivity and influences the molecule’s conformational stability. Industrially synthesized through controlled oxidation of corresponding alcohols or selective hydrogenation of aromatic precursors, this compound represents a modern approach to creating structurally complex odorants not found in nature. Its particular geometry allows for interesting stereoelectronic effects that contribute to its unique olfactory properties.
Physical & Chemical Properties
| State | Liquid |
|---|---|
| Color | Colorless to pale yellow |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-1% | Up to 3% | Used as an effect modifier |
| Functional Fragrance | 0.01-0.1% | Up to 0.5% | For freshness boost |
| Home Care | 0.001-0.01% | Up to 0.05% | Used in trace amounts for lift |
Classic Accords
Tip: Stabilize in ethanol before adding to polar bases to prevent unwanted polymerization.
Alternatives & Comparisons
For similar green-apple top notes with better stability in alkaline systems. Less metallic but more fruity character.
When a more floral, less green effect is desired. Provides similar longevity with softer diffusion.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted under IFRA standards, but recommended usage below 3% in finished products due to limited safety data.
GHS Classification
RIFM Assessment
Under evaluation – preliminary data suggests moderate skin sensitization potential at high concentrations.
Sustainability
As a purely synthetic material, production is not dependent on natural resources but requires careful management of chemical precursors. The synthesis route has been optimized to minimize waste, though energy requirements remain moderate. Future developments may focus on biocatalytic production methods to improve sustainability profile.
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References
- IFRA Standards Library (2023). Restricted Materials List. IFRA
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID70889263
Physical Properties
| Molecular Weight | 136.194 g/mol🔬 EPA CompTox |
| Density | 1.027 g/cm^3📊 OPERA |
| Boiling Point | 213.526 °C📊 OPERA |
| Melting Point | 8.744 °C📊 OPERA |
| Flash Point | 81.634 °C📊 OPERA |
| Refractive Index | 1.632 Dimensionless📊 OPERA |
| Molar Volume | 125.175 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.297 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.297 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.297 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.45 Log10 unitless📊 OPERA |
| Water Solubility | 0.011 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.182 mmHg📊 OPERA |
| Viscosity | 1.974 cP📊 OPERA |
| Surface Tension | 54.935 dyn/cm📊 OPERA |
| Thermal Conductivity | 132.199 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 | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 44.659 cm^3/mol📊 OPERA |
| Polarizability | 17.704 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.
