(+/-)-4-Ethyloctanal (CAS 58475-04-0) — Green Top to middle Note Fragrance Ingredient
(+/-)-4-Ethyloctanal
CAS 58475-04-0
What Is (+/-)-4-Ethyloctanal?
(+/-)-4-Ethyloctanal is a synthetic fragrance ingredient used to add fresh, green, and slightly metallic nuances to perfumes. You’ll find it in modern floral and citrus fragrances. This aldehyde brings a crisp, contemporary edge to compositions, often used to create ‘clean’ or ‘watery’ effects in body care products and fine fragrances.
Safety Profile
USE WITH AWARENESSWhat Does (+/-)-4-Ethyloctanal Smell Like?
4-Ethyloctanal opens with a burst of sharp green freshness reminiscent of crushed stems, evolving into a clean metallic nuance like raindrops on stainless steel. The dry-down reveals a surprisingly warm, slightly fatty character akin to candle wax, with a subtle citrus peel bitterness lingering in the background. At higher concentrations, it develops an almost aquatic quality, making it valuable for modern ‘blue’ fragrances.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to enhance the aquatic freshness, contributing to the signature ‘shower-fresh’ effect that made this fragrance revolutionary.
Provides the crisp, dewy top note that complements the lotus accord, creating the illusion of water droplets on petals.
2D Molecular Structure
SMILES: CCCCC(CC)CCC=O
Chemistry, Properties & Perfumer Guide
The Chemistry
This branched-chain aldehyde belongs to the family of medium-chain aldehydes, characterized by their potent odor properties. Synthesized through hydroformylation of 3-ethylheptene, its racemic form (±) is typically used in perfumery. The ethyl branch at position 4 creates steric hindrance that modifies its reactivity compared to linear aldehydes.
Physical & Chemical Properties
| Boiling Point | ~200°C (estimated) |
|---|---|
| Density | ~0.82 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | For fresh top notes |
| Functional Fragrance | 0.05-0.2% | Up to 0.5% | In detergents and soaps |
Classic Accords
Tip: Use below 1% to avoid overwhelming compositions with its metallic character.
Alternatives & Comparisons
Linear version provides sharper citrus character without the metallic nuance, better for traditional citrus accords.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific restrictions under IFRA standards.
GHS Classification
RIFM Assessment
RIFM assessment pending for this material.
Sustainability
As a synthetic material, production requires petrochemical feedstocks but has lower environmental impact than natural alternatives requiring agricultural land. Modern synthesis routes aim to minimize waste and energy consumption.
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 58475-04-0Physical Properties
| Molecular Weight | 156.26 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.5🔬 PubChem |
| Boiling Point | 201 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.168💻 Calculated |
| SMILES | CCCCC(CC)CCC=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | citrusgreen• leffingwell |
| Functional Groups | aldehyde💻 RDKit |
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: DTXSID40974019
Physical Properties
| Molecular Weight | 156.269 g/mol🔬 EPA CompTox |
| Density | 0.822 g/cm^3📊 OPERA |
| Boiling Point | 202 °C🔬 EPA CTX |
| Melting Point | -4.338 °C📊 OPERA |
| Flash Point | 71.313 °C📊 OPERA |
| Refractive Index | 1.421 Dimensionless📊 OPERA |
| Molar Volume | 191.298 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.822 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.822 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.822 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.99 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.272 mmHg📊 OPERA |
| Viscosity | 1.61 cP📊 OPERA |
| Surface Tension | 25.858 dyn/cm📊 OPERA |
| Thermal Conductivity | 138.242 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 | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 48.523 cm^3/mol📊 OPERA |
| Polarizability | 19.236 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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