Theaspirane (CAS 36431-72-8) — Woody Middle Note Fragrance Ingredient

ByThe Good Scents
Woody · Green

Theaspirane

CAS 36431-72-8

Origin
synthetic
Note
Middle
IFRA
Generally safe
Data as of: Apr 2026

What Is Theaspirane?

Theaspirane is a synthetic fragrance ingredient used to add depth and complexity to perfumes. It’s often found in modern floral and woody fragrances. This molecule matters because it helps create sophisticated scent profiles that evolve beautifully on skin, bridging natural and synthetic elements in perfumery.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
✓ Safe in regulated products
⚠ Use standard precautions
CAS
36431-72-8
Formula
Mixture
MW
Variable
Odor Family
Woody · Green
Layer 1 · Enthusiast

What Does Theaspirane Smell Like?

Theaspirane unfolds with an initial burst of crisp, slightly herbal greenness that recalls crushed tea leaves. This evolves into a heart of warm woody tones with subtle floral undertones, like walking through a sun-dappled forest after rain. The dry-down reveals a sophisticated base of dry, slightly spicy woods with a whisper of ambery sweetness that lingers close to the skin.

Scent Profile
Layer 2

2D Molecular Structure

1-Oxaspiro(4.5)dec-6-ene, 2,6,10,10-tetramethyl-, (2S,5S)-

SMILES: [H][C@]1(C)CC[C@@]2(O1)C(C)=CCCC2(C)C

Chemistry, Properties & Perfumer Guide

The Chemistry

Theaspirane is a synthetic bicyclic ether belonging to the class of pyran derivatives. While not found in nature, it mimics structural elements of terpenoid compounds. It’s typically synthesized through cyclization reactions of appropriate precursors under acidic conditions. The molecule’s rigid bicyclic structure contributes to its stability and distinctive olfactory properties.

Physical & Chemical Properties

Perfumer Guide

Note Position
Middle
Volatility
Moderate (2-4 hours)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance1-3%Up to 5%Adds woody-green complexity
Functional Fragrance0.5-1%Up to 2%Background modifier

Classic Accords

Tip: Use to bridge green top notes with woody base notes in masculine and unisex compositions.

Alternatives & Comparisons

1
Vertofix CAS 68039-49-6

Similar woody character but with stronger cedar aspects. Use when needing more pronounced wood notes.

2
Timberol CAS 28219-60-5

Woodier alternative with less green character. Better for pure woody accords.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

No IFRA restrictions currently apply to Theaspirane.

RIFM Assessment

RIFM has evaluated Theaspirane and found it safe for current use levels.

Sustainability

As a synthetic material, Theaspirane has minimal environmental impact in production compared to natural alternatives. Its efficient synthesis from readily available precursors makes it a sustainable choice for modern perfumery when used at appropriate levels.

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References

    Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

    Report a data error

    Perfumers Notes

    Odor Profile

    Camphoreous, fruity, sweet, woody.

    Regulatory Status

    FEMA GRAS #3774 | IOFI: 13.098

    Standard Dilution

    10% in DPG (standard dilution for most fragrance materials)

    Typical Usage Levels

    FEMA GRAS (#3774) — typical use 0.01-5% in fragrance.

    Ingredient Data Sheet

    CAS 36431-72-8

    Physical Properties

    Molecular Weight194.31 g/mol🔬 PubChem
    LogP (Octanol-Water)3🔬 PubChem
    Boiling Point68 °C🔬 EPA CompTox
    log Kp (skin permeability)-1.755💻 Calculated
    SMILESCC1CCC2(O1)C(=CCCC2(C)C)C🔬 PubChem

    Volatility & Performance

    Fragrance NoteTop💻 Calculated

    Odor & Flavor

    Primary Descriptorscamphoraceousfruitysweetwoody• leffingwell
    Functional Groupsetheralkene💻 RDKit
    Theaspirane is fruity, woody, sweetish and ionone-like camphoraceous.📖 Fenaroli
    Data Sources & Attribution
    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: DTXSID3047055

    Physical Properties

    Molecular Weight 194.318 g/mol🔬 EPA CompTox
    Density 0.942 g/cm^3🔬 EPA CTX
    Boiling Point 242.142 °C📊 OPERA
    Melting Point 19.296 °C📊 OPERA
    Flash Point 95.633 °C📊 OPERA
    Refractive Index 1.488 Dimensionless📊 OPERA
    Molar Volume 206.612 cm^3/mol📊 OPERA

    Partition & Solubility

    LogP (Octanol-Water) 4.301 Log10 unitless📊 OPERA
    LogD (pH 5.5) 4.301 Log10 unitless📊 OPERA
    LogD (pH 7.4) 4.301 Log10 unitless📊 OPERA
    LogKoa (Octanol-Air) 5.78 Log10 unitless📊 OPERA
    Water Solubility 0.007 mol/L📊 OPERA
    Henry's Law Constant 0.001 atm-m3/mole📊 OPERA

    Transport Properties

    Vapor Pressure 0.275 mmHg📊 OPERA
    Viscosity 4.252 cP📊 OPERA
    Surface Tension 29.982 dyn/cm📊 OPERA
    Thermal Conductivity 115.144 mW/(m*K)📊 OPERA

    Molecular Descriptors

    Topological Polar Surface Area 9.23 Ų💻 Computed
    H-Bond Donors 0 count💻 Computed
    H-Bond Acceptors 1 count💻 Computed
    Rotatable Bonds 0 count💻 Computed
    Aromatic Rings 0 count💻 Computed
    Molar Refractivity 59.566 cm^3/mol📊 OPERA
    Polarizability 23.614 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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