1-Oxaspiro[4.5]decan-2-one, 8-(1-methylethyl)-, trans- (CAS 4625-90-5) — Woody Middle to Base Note Fragrance Ingredient
1-Oxaspiro[4.5]decan-2-one, 8-(1-methylethyl)-, trans-
CAS 4625-90-5
What Is 1-Oxaspiro[4.5]decan-2-one, 8-(1-methylethyl)-, trans-?
1-Oxaspiro[4.5]decan-2-one is a synthetic fragrance ingredient occasionally used in modern perfumery. It belongs to the spirocyclic lactone family, contributing unique woody-musk and amber nuances. While not commonly found in consumer products, it may appear in niche or avant-garde fragrances where perfumers seek unusual olfactory effects. This material matters because it represents how synthetic chemistry expands the perfumer’s palette beyond natural sources, enabling the creation of novel scent profiles that can’t be achieved with traditional ingredients alone.
Safety Profile
USE WITH AWARENESSWhat Does 1-Oxaspiro[4.5]decan-2-one, 8-(1-methylethyl)-, trans- Smell Like?
This spirocyclic lactone presents a complex olfactory profile that evolves intriguingly. Initially, it offers a crisp, almost ozonic top note with subtle metallic undertones, like cold steel warmed by skin. As it develops, a creamy lactonic character emerges, reminiscent of warm milk with a whisper of coconut. The dry-down reveals its true depth – a sophisticated woody-musk foundation with faint ambery nuances, like antique furniture polished with beeswax. Throughout its evolution, there’s a persistent clean, slightly mineralic quality that prevents the scent from becoming heavy, making it surprisingly versatile despite its complexity.
2D Molecular Structure
SMILES: CC(C)[C@H]1CC[C@@]2(CCC(=O)O2)CC1
Chemistry, Properties & Perfumer Guide
The Chemistry
1-Oxaspiro[4.5]decan-2-one belongs to the spirocyclic lactone class of compounds, characterized by their unique oxygen-containing ring systems bridged across cyclic structures. These molecules are entirely synthetic with no known natural counterparts. Synthesis typically involves cyclization reactions of appropriate keto-acids or hydroxy-acid precursors, often using strong acid catalysts. The spiro structure creates significant conformational constraints that influence both the molecule’s odor properties and its stability in formulations. While the trans configuration is more common in perfumery applications, some syntheses may produce cis isomers which typically have different olfactory characteristics.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | Low (high potency) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Used as a modifier for woody accords |
| Functional Fragrance | 0.01-0.1% | Up to 0.2% | Adds sophistication to fabric care products |
| Home Care | 0.05-0.3% | Up to 0.5% | Provides long-lasting woody notes |
Classic Accords
Tip: Use in trace amounts to add depth to woody accords without overwhelming other ingredients.
Alternatives & Comparisons
Offers similar spirocyclic structure but with more pronounced floral-green facets, useful when needing brighter top notes.
Provides comparable muskiness with better diffusion, ideal for applications requiring more projection.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards. No specific usage limits established.
RIFM Assessment
No RIFM safety assessment currently available for this material.
Sustainability
As a fully synthetic material, 1-Oxaspiro[4.5]decan-2-one doesn’t impact natural resources directly. However, its synthesis requires petrochemical feedstocks and energy-intensive processes. Some manufacturers are exploring greener synthetic routes using biocatalysis or more efficient cyclization methods. Being highly potent, it’s used in very small quantities, which reduces its overall environmental footprint compared to materials requiring higher dosing levels.
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Physicochemical Properties
DTXSID: DTXSID801021225
Physical Properties
| Molecular Weight | 196.29 g/mol🔬 EPA CompTox |
| Density | 0.99 g/cm^3📊 OPERA |
| Boiling Point | 279.848 °C📊 OPERA |
| Melting Point | 65.483 °C📊 OPERA |
| Flash Point | 112.361 °C📊 OPERA |
| Refractive Index | 1.481 Dimensionless📊 OPERA |
| Molar Volume | 194.33 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.432 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.432 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.432 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.91 Log10 unitless📊 OPERA |
| Water Solubility | 0.004 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.011 mmHg📊 OPERA |
| Viscosity | 2.263 cP📊 OPERA |
| Surface Tension | 34.026 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 | 1 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 55.341 cm^3/mol📊 OPERA |
| Polarizability | 21.939 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.
