2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane (CAS 69103-20-4) — Green Top Note Fragrance Ingredient

ByThe Good Scents
Green · Woody

2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane

CAS 69103-20-4

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

What Is 2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane?

2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane is a synthetic fragrance ingredient used to add fresh, green nuances to perfumes. It’s found in air fresheners and cleaning products. This molecule contributes crisp top notes that evoke nature, though it’s entirely lab-created. Its precise structure allows perfumers to dial in specific green characteristics without the variability of natural materials.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
✓ Not classified as hazardous
⚠ Limited safety data available
CAS
69103-20-4
Formula
Mixture
MW
Variable
Odor Family
Green · Woody
Layer 1 · Enthusiast

What Does 2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane Smell Like?

This synthetic molecule delivers a piercing green freshness reminiscent of crushed leaves and unripe fruit. The initial burst has a slightly metallic sharpness that quickly mellows into a clean, herbaceous quality. Unlike natural green notes, it maintains remarkable stability without turning musty or bitter. The drydown reveals subtle woody undertones that prevent the green character from becoming overly harsh.

Scent Profile
Layer 2

2D Molecular Structure

2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane

SMILES: CC(C=C)=CCC1OC1(C)C

Chemistry, Properties & Perfumer Guide

The Chemistry

2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane belongs to the class of epoxy terpenes. Its structure features a strained epoxide ring attached to a conjugated diene system, which contributes to its reactivity and distinctive odor profile. The synthesis typically involves the epoxidation of a terpene precursor under controlled conditions. The molecule’s compact size and functional groups make it highly volatile and impactful at low concentrations.

Physical & Chemical Properties

Molecular WeightNot available
Boiling PointNot available

Perfumer Guide

Note Position
Top
Volatility
High (15-30 min)
Blending
Good
ApplicationTypical %RangeNotes
Functional Fragrance0.1-1%Up to 2%Provides fresh top notes
Fine Fragrance0.05-0.5%Up to 1%Used for green accents

Classic Accords

Tip: Use sparingly to avoid overwhelming other top notes.

Alternatives & Comparisons

1
Stemone CAS 67634-15-5

Provides similar green effects with more floral character and better stability in bases.

2
Verdox CAS 88-41-5

Offers green woody notes with greater tenacity and less sharpness.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

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

IFRA Status

No specific IFRA restrictions identified.

RIFM Assessment

No RIFM safety assessment publicly available.

Sustainability

As a synthetic material, this ingredient avoids agricultural impacts but carries energy costs from petrochemical sourcing and manufacturing. Its potency means small quantities are effective, reducing overall environmental load compared to less powerful green notes.

Explore 2,2-Dimethyl-3-(3-methyl-2,4-pentadienyl)oxirane

Browse essential oils and aroma compounds.

Browse on iHerb →

Affiliate disclosure: we may earn a small commission at no extra cost to you.

References

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

    Report a data error

    Ingredient Data Sheet

    CAS 69103-20-4

    Physical Properties

    Molecular Weight152.23 g/mol🔬 PubChem
    LogP (Octanol-Water)2.9🔬 PubChem
    Boiling Point197.9 °C🔬 EPA CompTox
    Vapor Pressure0.66 mmHg @ 25°C📊 OPERA
    Flash Point72.7 °C🔬 EPA CompTox
    Involatility Index0.0577💻 Calculated
    log Kp (skin permeability)-1.57💻 Calculated
    SMILESCC(=CCC1C(O1)(C)C)C=C🔬 PubChem

    Volatility & Performance

    Fragrance NoteTop💻 Calculated
    Volatility ClassSlow💻 Calculated
    Persistence Score0.5 / 5💻 Calculated

    Odor & Flavor

    Primary Descriptorsgreenwoody• leffingwell
    Functional Groupsetheralkene💻 RDKit
    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: DTXSID3052436

    Physical Properties

    Molecular Weight 152.237 g/mol🔬 EPA CompTox
    Density 0.881 g/cm^3🔬 EPA CTX
    Boiling Point 197.85 °C🔬 EPA CTX
    Melting Point -21.705 °C📊 OPERA
    Flash Point 72.744 °C🔬 EPA CTX

    Partition & Solubility

    LogP (Octanol-Water) 484.995 Log10 unitless🔬 EPA CTX
    Water Solubility 0.013 mol/L📊 OPERA

    Transport Properties

    Vapor Pressure 0.504 mmHg🔬 EPA CTX
    Viscosity 0.889 cP📊 OPERA

    Molecular Descriptors

    Topological Polar Surface Area 12.53 Ų💻 Computed
    H-Bond Donors 0 count💻 Computed
    H-Bond Acceptors 1 count💻 Computed
    Rotatable Bonds 3 count💻 Computed
    Aromatic Rings 0 count💻 Computed
    Molar Refractivity 47.52 cm^3/mol💻 Computed

    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.

    Similar Posts