Oxacycloheptadec-11-en-2-one (CAS 36508-31-3) — Musky Base Note Fragrance Ingredient
Oxacycloheptadec-11-en-2-one
CAS 36508-31-3
What Is Oxacycloheptadec-11-en-2-one?
Oxacycloheptadec-11-en-2-one is a synthetic musk compound used in modern perfumery. It’s found in premium fragrances where a clean, musky foundation is desired. This ingredient matters because it provides long-lasting warmth without animalic notes, making it popular in gender-neutral and contemporary scents that avoid traditional musk sources.
Safety Profile
USE WITH AWARENESSWhat Does Oxacycloheptadec-11-en-2-one Smell Like?
A refined macrocyclic musk with a surprisingly clean character. Opens with a crisp, almost ozonic freshness that quickly settles into a skin-like warmth. Unlike animalic musks, this remains discreet – imagine freshly laundered cashmere warmed by body heat. The dry-down is remarkably persistent, leaving a subtle satin-like trail that blends seamlessly with skin chemistry. Lacks the sweaty undertones of traditional musks, instead offering a modern interpretation that’s both intimate and sophisticated.
2D Molecular Structure
SMILES: O=C1CCCCCCCCC=CCCCCCO1
Chemistry, Properties & Perfumer Guide
The Chemistry
Oxacycloheptadec-11-en-2-one belongs to the macrocyclic musk family, characterized by their large ring structures (typically 15-17 atoms). These synthetic musks were developed as alternatives to nitro musks and animal-derived muscone. The oxygen heteroatom in the ring structure modifies the odor profile compared to purely hydrocarbon macrocycles. Synthesis typically involves ring-closing metathesis of long-chain dienes followed by oxidation steps to establish the ketone functionality.
Physical & Chemical Properties
| Molecular Class | Macrocyclic ketone |
|---|---|
| Odor Threshold | Extremely low (ppt range) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Musky foundation |
| Detergents | 0.01-0.1% | Up to 0.3% | Lingering freshness |
Classic Accords
Tip: Use below 5% to avoid overwhelming other notes – its power comes from persistence, not projection.
Alternatives & Comparisons
More affordable macrocyclic musk with similar clean character but slightly sweeter profile.
Higher-end alternative with more animalic depth and superior diffusion properties.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA. Listed on Annex II of EU Cosmetics Regulation as approved fragrance ingredient.
RIFM Assessment
RIFM has evaluated similar macrocyclic musks as safe at current usage levels, though environmental persistence is monitored.
Sustainability
As a synthetic musk, this avoids the ethical concerns of animal-derived musks but raises questions about environmental persistence. Modern wastewater treatment struggles to fully remove macrocyclic musks, leading to trace accumulation in waterways. However, it’s more biodegradable than older nitro musks. Production typically involves petrochemical feedstocks, though some manufacturers are exploring bio-based synthesis routes.
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References
- IFRA Standards Library IFRA
- EU Cosmetics Regulation Annex II EC Cosmetics
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorLayer 3 · Practical
- Molecular Weight: 252.39 g/mol
- LogP (XLogP): 5.50
Ingredient Data Sheet
CAS 36508-31-3Physical Properties
| Molecular Weight | 252.39 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 5.5🔬 PubChem |
| Boiling Point | 305 °C🔬 EPA CompTox |
| Vapor Pressure | 0 mmHg @ 25°C📊 OPERA |
| Flash Point | 168.2 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -0.335💻 Calculated |
| SMILES | C1CCCCC(=O)OCCCCCC=CCCC1🔬 PubChem |
Volatility & Performance
| Fragrance Note | Base💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 14.8 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | esteretheralkene💻 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: DTXSID2074908
Physical Properties
| Molecular Weight | 252.398 g/mol🔬 EPA CompTox |
| Density | 0.912 g/cm^3📊 OPERA |
| Boiling Point | 356.428 °C📊 OPERA |
| Melting Point | 31.131 °C📊 OPERA |
| Flash Point | 168.094 °C📊 OPERA |
| Refractive Index | 1.445 Dimensionless📊 OPERA |
| Molar Volume | 282.408 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 5.705 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 5.705 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 5.705 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 8.91 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0 mmHg📊 OPERA |
| Viscosity | 5.893 cP📊 OPERA |
| Surface Tension | 28.857 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 75.127 cm^3/mol📊 OPERA |
| Polarizability | 29.783 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.
