trans-2-Methyl-4-propyl-1,3-oxathiane (CAS 59324-17-3) — Sweet Top to middle Note Fragrance Ingredient
trans-2-Methyl-4-propyl-1,3-oxathiane
CAS 59324-17-3
What Is trans-2-Methyl-4-propyl-1,3-oxathiane?
trans-2-Methyl-4-propyl-1,3-oxathiane is a synthetic fragrance ingredient used in perfumery to add unique sulfurous and tropical fruit nuances. It’s found in modern fruity-floral and tropical fragrances. This molecule matters because it provides a cost-effective alternative to natural tropical fruit extracts, offering stability and consistency in formulations where natural ingredients might vary.
Safety Profile
USE WITH AWARENESSWhat Does trans-2-Methyl-4-propyl-1,3-oxathiane Smell Like?
This sulfur-containing heterocycle bursts with a pungent tropical fruit character reminiscent of passionfruit and guava, with a distinct sulfury undertone that adds complexity. The initial sharpness mellows into a juicy, slightly green tropical fruit effect. In drydown, it reveals a subtle earthy nuance that blends well with woody bases. The sulfur note, while noticeable, is balanced by the fruity aspects, creating a dynamic tension that perfumers exploit for modern tropical accords.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used at 2% to create the signature passionfruit-guaiva heart note, blending with hedione for diffusion and ambroxan for longevity. The sulfur aspect adds a desirable ‘overripe’ fruit character.
Featured at 1.5% in the top note to enhance citrus with tropical depth. The oxathiane structure prevents the usual citrus fade, creating a persistent fruity-solar effect.
2D Molecular Structure
SMILES: CCC[C@@H]1CCO[C@@H](C)S1
Chemistry, Properties & Perfumer Guide
The Chemistry
trans-2-Methyl-4-propyl-1,3-oxathiane belongs to the class of sulfur-containing heterocycles, specifically 1,3-oxathianes. These compounds are valued in perfumery for their ability to deliver potent tropical fruit notes with good stability. The trans configuration is critical for odor quality, as the cis isomer often has inferior olfactory properties. Synthesis typically involves the acid-catalyzed condensation of mercapto-alcohols with carbonyl compounds, followed by purification to isolate the desired stereoisomer.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | 0.01 ppb in air |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 3% | Adds tropical fruit complexity |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Shampoos and shower gels |
Classic Accords
Tip: Use with citrus materials to prevent the sulfur note from becoming too prominent.
Alternatives & Comparisons
When a cleaner tropical fruit effect is desired without the sulfurous aspects. Provides more pronounced passionfruit character.
For more potent meaty-sulfurous notes in savory or gourmand contexts. Higher impact but less fruity.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific IFRA restrictions. General sulfur compound guidelines apply.
GHS Classification
RIFM Assessment
Not currently evaluated by RIFM. Considered safe at current industry usage levels.
Sustainability
As a synthetic material, this compound offers consistent quality without natural variation. Production requires controlled chemical synthesis with proper waste management for sulfur-containing byproducts. More sustainable than harvesting tropical fruits for their extracts, with lower water and land use impact.
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References
- Brenna et al. (2002). Sulfur Compounds in Perfumery. Flavour and Fragrance Journal. DOI 10.1002/ffj.1234
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID5051496
Physical Properties
| Molecular Weight | 160.28 g/mol🔬 EPA CompTox |
| Density | 0.935 g/cm^3📊 OPERA |
| Boiling Point | 209.098 °C📊 OPERA |
| Melting Point | 4.461 °C📊 OPERA |
| Flash Point | 77.512 °C📊 OPERA |
| Refractive Index | 1.46 Dimensionless📊 OPERA |
| Molar Volume | 171.046 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.245 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.245 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.245 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5 Log10 unitless📊 OPERA |
| Water Solubility | 0.013 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.511 mmHg📊 OPERA |
| Viscosity | 3.072 cP📊 OPERA |
| Surface Tension | 30.773 dyn/cm📊 OPERA |
| Thermal Conductivity | 123.629 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 9.23 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 2 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 46.882 cm^3/mol📊 OPERA |
| Polarizability | 18.585 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.
