2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)- (CAS 21016-46-6) — Sweet Top Note Fragrance Ingredient

ByThe Good Scents
Sweet · Green

2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)-

CAS 21016-46-6

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

What Is 2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)-?

2-Pentenoic acid, 2,4-dimethyl-, ethyl ester is a synthetic fragrance ingredient used in modern perfumery. It contributes fruity, slightly green nuances to compositions. Consumers encounter it in niche fragrances and some household products for its ability to enhance natural fruit accords without overpowering.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
✓ Safe in regulated products
⚠ Check for individual sensitivities
CAS
21016-46-6
Formula
Mixture
MW
Variable
Odor Family
Sweet · Green
Layer 1 · Enthusiast

What Does 2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)- Smell Like?

This ester delivers a crisp, fruity-green character reminiscent of underripe apples and freshly cut stems. The initial burst evolves into a more rounded, slightly tropical fruitiness over time, with a dry-down that hints at faint woody undertones. Its behavior is linear but provides excellent lift in the top notes.

Scent Profile
Layer 2

2D Molecular Structure

2-Pentenoic acid, 2,4-dimethyl-, ethyl ester, (2E)-

SMILES: CCOC(=O)C(\C)=C\C(C)C

Chemistry, Properties & Perfumer Guide

The Chemistry

2-Pentenoic acid, 2,4-dimethyl-, ethyl ester is a branched-chain unsaturated ester. It’s synthesized through esterification reactions of the corresponding acid. The (E)-configuration contributes to its specific odor profile. As a synthetic molecule, it’s not found in nature but mimics certain fruity aspects of natural esters.

Physical & Chemical Properties

Boiling PointNot available
DensityNot available

Perfumer Guide

Note Position
Top
Volatility
Medium (1-2 hours)
Blending
Good
ApplicationTypical %RangeNotes
Fine Fragrance0.5-2%Up to 5%Adds fruity freshness
Functional Fragrances0.1-1%Up to 3%Light fruity modifier

Classic Accords

Tip: Use to brighten fruity compositions without adding sweetness.

Alternatives & Comparisons

1
Ethyl-2-methylpentanoate CAS 39255-32-8

For a more intense, jammy fruit effect with similar longevity.

2
Hexyl acetate CAS 142-92-7

When a cleaner, pear-like fruitiness is desired.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

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

IFRA Status

No IFRA restrictions currently apply.

RIFM Assessment

No specific RIFM assessment found for this material.

Sustainability

As a synthetic material, its production is controlled in industrial settings. The environmental impact depends on manufacturing processes and raw material sourcing.

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References

  1. PubChem Compound Summary CID not available

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

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Ingredient Data Sheet

CAS 21016-46-6

Physical Properties

Molecular Weight156.22 g/mol🔬 PubChem
LogP (Octanol-Water)2.4🔬 PubChem
Boiling Point183 °C🔬 EPA CompTox
Vapor Pressure1.349 mmHg @ 25°C📊 OPERA
Flash Point65.5 °C🔬 EPA CompTox
Involatility Index0.1163💻 Calculated
log Kp (skin permeability)-1.949💻 Calculated
SMILESCCOC(=O)C(=CC(C)C)C🔬 PubChem

Volatility & Performance

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

Odor & Flavor

Functional Groupsesteretheralkene💻 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: DTXSID0074392

Physical Properties

Molecular Weight 156.225 g/mol🔬 EPA CompTox
Density 0.903 g/cm^3📊 OPERA
Boiling Point 185.482 °C📊 OPERA
Melting Point -41.223 °C📊 OPERA
Flash Point 66.953 °C📊 OPERA
Refractive Index 1.434 Dimensionless📊 OPERA
Molar Volume 174.371 cm^3/mol📊 OPERA

Partition & Solubility

LogP (Octanol-Water) 2.984 Log10 unitless📊 OPERA
LogD (pH 5.5) 2.984 Log10 unitless📊 OPERA
LogD (pH 7.4) 2.984 Log10 unitless📊 OPERA
LogKoa (Octanol-Air) 4.43 Log10 unitless📊 OPERA
Water Solubility 0.031 mol/L📊 OPERA
Henry's Law Constant 0 atm-m3/mole📊 OPERA

Transport Properties

Vapor Pressure 0.712 mmHg📊 OPERA
Surface Tension 25.936 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 3 count💻 Computed
Aromatic Rings 0 count💻 Computed
Molar Refractivity 45.379 cm^3/mol📊 OPERA
Polarizability 17.99 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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