1-(1,2,3,5,6,7,8,8a-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one (CAS 68155-66-8) — Musky Base Note Fragrance Ingredient

Musky · Woody

1-(1,2,3,5,6,7,8,8a-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one

CAS 68155-66-8

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

What Is 1-(1,2,3,5,6,7,8,8a-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one?

This synthetic musk compound is used as a long-lasting base note in modern perfumery. Found in laundry detergents, fabric softeners, and premium fragrances, it provides a clean, powdery character. As a cost-effective alternative to natural musks, it plays a crucial role in making everyday products smell pleasant while maintaining affordability.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
Safe in regulated products
Check for allergen labeling
CAS
68155-66-8
Formula
Mixture
MW
Variable
Odor Family
Musky · Woody
Layer 1 · Enthusiast

What Does 1-(1,2,3,5,6,7,8,8a-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one Smell Like?

This musk presents a soft, powdery aura with subtle laundry-fresh undertones. Imagine sun-dried linen infused with the faintest whisper of baby powder – not sweet, but comforting. Over hours, it evolves into a skin-like warmth, blending seamlessly with body chemistry. The dry-down is remarkably persistent, leaving a barely-there impression of cleanliness that lingers for days on fabrics.

Scent Profile

In Famous Fragrances

Fragrance associations may not reflect actual formulations.

Used here to create the illusion of sun-baked laundry, blending with synthetic aldehydes for a fabric-softener freshness that lasts through multiple washes.

Glossier You(Glossier, 2017)

Provides the molecular backbone for this ‘skin-but-better’ scent, adding lasting power to the ambroxan and iris accord without overpowering.

Layer 2

2D Molecular Structure

1-(2,3,8,8-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalen-2-yl)ethan-1-one

SMILES: CC1C=C2CCCC(C)(C)C2CC1(C)C(C)=O

Chemistry, Properties & Perfumer Guide

The Chemistry

A synthetic polycyclic musk belonging to the tetralin class. Developed as an alternative to nitro musks, it features a complex hydrogenated naphthalene structure. Industrially produced via Friedel-Crafts acylation followed by hydrogenation. The rigid tetracyclic framework contributes to exceptional stability and longevity in formulations. Unlike macrocyclic musks, this compound is achiral and manufactured as a single isomer.

Physical & Chemical Properties

Boiling PointN/A
DensityN/A

Perfumer Guide

Note Position
Base
Volatility
Very low (days)
Blending
Excellent
ApplicationTypical %RangeNotes
Laundry Care0.1-0.5%Up to 1%Provides lasting freshness
Fine Fragrance0.5-2%Up to 3%Musky foundation

Classic Accords

Tip: Use with white musks to create diffusion without overwhelming sweetness.

Alternatives & Comparisons

1
Galaxolide CAS 1222-05-5

When a brighter, more diffusive musk character is desired.

2
Ethylene Brassylate CAS 105-95-3

For a smoother, more rounded musk effect in fine fragrances.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

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

IFRA Status

Not currently restricted by IFRA.

EU Allergen Declaration

Not listed as an EU allergen.

RIFM Assessment

RIFM assessment confirms safe use at current industry levels.

Sustainability

As a purely synthetic material, production avoids wildlife impacts associated with natural musk harvesting. However, the petroleum-based synthesis raises carbon footprint concerns. Recent advances in catalytic hydrogenation have improved energy efficiency. Not known to bioaccumulate significantly.

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References

  1. IFRA Standards Library IFRA
  2. PubChem Compound Summary PubChem

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

Report a data error

Physicochemical Properties

DTXSID: DTXSID9052397

Physical Properties

Molecular Weight 234.383 g/mol🔬 EPA CompTox
Density 0.944 g/cm^3📊 OPERA
Boiling Point 294.939 °C📊 OPERA
Melting Point 40.902 °C📊 OPERA
Flash Point 135.024 °C📊 OPERA
Refractive Index 1.493 Dimensionless📊 OPERA
Molar Volume 247.089 cm^3/mol📊 OPERA

Partition & Solubility

LogP (Octanol-Water) 4.571 Log10 unitless📊 OPERA
LogD (pH 5.5) 4.571 Log10 unitless📊 OPERA
LogD (pH 7.4) 4.571 Log10 unitless📊 OPERA
LogKoa (Octanol-Air) 7.51 Log10 unitless📊 OPERA
Water Solubility 0 mol/L📊 OPERA
Henry's Law Constant 0 atm-m3/mole📊 OPERA

Transport Properties

Vapor Pressure 0.001 mmHg📊 OPERA
Surface Tension 32.09 dyn/cm📊 OPERA
Thermal Conductivity 115.592 mW/(m*K)📊 OPERA

Molecular Descriptors

Topological Polar Surface Area 17.07 Ų💻 Computed
H-Bond Donors 0 count💻 Computed
H-Bond Acceptors 1 count💻 Computed
Rotatable Bonds 1 count💻 Computed
Aromatic Rings 0 count💻 Computed
Molar Refractivity 71.809 cm^3/mol📊 OPERA
Polarizability 28.467 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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