5-Methyl-2-phenyl-2-hexenal (CAS 21834-92-4) — Sweet Top to middle Note Fragrance Ingredient
5-Methyl-2-phenyl-2-hexenal
CAS 21834-92-4
What Is 5-Methyl-2-phenyl-2-hexenal?
5-Methyl-2-phenyl-2-hexenal is a synthetic fragrance ingredient used to add fruity, floral, and slightly woody nuances to perfumes. It’s found in various personal care products and fine fragrances. This molecule matters because it contributes unique olfactory properties that can’t be easily replicated with natural extracts, allowing perfumers to create novel scent profiles.
Safety Profile
USE WITH AWARENESSWhat Does 5-Methyl-2-phenyl-2-hexenal Smell Like?
5-Methyl-2-phenyl-2-hexenal opens with a bright, fruity character reminiscent of ripe apples and pears, with subtle floral undertones. As it evolves, it reveals a deeper, slightly woody base that adds complexity. The dry-down is smooth and persistent, leaving a delicate fruity-floral trail. Its odor profile bridges the gap between fresh top notes and warmer heart notes, making it versatile in compositions.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to enhance the fruity-floral heart, contributing to the signature juicy pear note that defines this popular celebrity fragrance.
Adds a crisp, fruity dimension to the citrus top notes, helping create the refreshing yet sophisticated summer scent profile.
2D Molecular Structure
SMILES: CC(C)CC=C(C=O)C1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
5-Methyl-2-phenyl-2-hexenal belongs to the class of α,β-unsaturated aldehydes, known for their reactivity and distinctive odor profiles. While not found in nature, it’s synthesized through aldol condensation reactions. The phenyl group contributes to its stability and influences its odor characteristics. The molecule’s structure allows it to interact with both fruity and floral olfactory receptors.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Strength | Medium to strong |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Adds fruity-floral character |
| Body Care | 0.1-0.5% | Up to 1% | Used in moderation due to potency |
Classic Accords
Tip: Use in conjunction with citrus top notes to enhance freshness and with white florals to boost their fruity aspects.
Alternatives & Comparisons
Offers similar floral-jasmine character but with less fruity impact and better stability in alkaline formulations.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards.
RIFM Assessment
Under evaluation by RIFM for comprehensive safety assessment.
Sustainability
As a synthetic material, 5-Methyl-2-phenyl-2-hexenal doesn’t rely on natural resources but requires energy-intensive chemical processes. Its production can be optimized for minimal waste and environmental impact through green chemistry principles.
Explore 5-Methyl-2-phenyl-2-hexenal
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
Physicochemical Properties
DTXSID: DTXSID9047419
Physical Properties
| Molecular Weight | 188.27 g/mol🔬 EPA CompTox |
| Density | 0.973 g/cm^3🔬 EPA CTX |
| Boiling Point | 294.36 °C📊 OPERA |
| Melting Point | 28.319 °C📊 OPERA |
| Flash Point | 121.147 °C📊 OPERA |
| Refractive Index | 1.514 Dimensionless📊 OPERA |
| Molar Volume | 197.489 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.121 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.121 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.121 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.69 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.039 mmHg📊 OPERA |
| Viscosity | 4.293 cP📊 OPERA |
| Surface Tension | 33.741 dyn/cm📊 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 | 4 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 59.462 cm^3/mol📊 OPERA |
| Polarizability | 23.572 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.
![1,3,5-Triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[[4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl]- (CAS 40601-76-1) — Woody Base Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/1-3-5-triazine-2-4-6-1-768x439.webp)
