Iso E Super

SyntheticPOPULAR & WEIRDwoody · amber · velvet

BasePyramid

3/5Strength

172hTenacity

4Origins

Editorial noteWe own no rights to this material, its name or its trademark. This entry is independent editorial journalism, published under freedom of expression.

Specimen

Synthetic (no botanical source)

Definition

Warm, cedar-smooth, almost subliminal. Iso E Super registers less as a smell than as a presence — a woody haze that wraps the wearer and drifts at the edge of perception, appearing and disappearing as olfactory receptors saturate and reset.

WOODY SWEET AMBER WARM FRESH

OTNE ISO E SUPER

Instruments

Pyramid

TTop

HHeart

BBase

3/5Strength

Medium

odour strength

Tenacity on blotter

172hours · 7 days

1 h6 h24 h3 d7 d400 h

at 100 %

Producing countries

China Germany Japan USA

Scent

Smooth, cedar-toned, with a dry peppery edge and a warmth that reads as texture rather than scent. Drier and more abstract than sandalwood, less sharp than Virginia cedarwood, warmer and rounder than ambroxan's mineral projection. There is a faint amber sweetness underneath — not gourmand, more like sun-warmed plywood — and a skin-like quality that makes it feel personal. At threshold concentrations, it produces the sensation of standing near something warm and wooden without being able to identify the source.

Evolution over time

Immediately0 h

A soft cedar-like warmth, faintly peppery, diffusing outward from the first moments. More felt than smelled — registers as a warm wooden presence rather than a distinct note. Some wearers perceive almost nothing at first application.

After a few hours+ h

The characteristic fade-in-fade-out cycle begins. The woody-amber warmth deepens, gains a smooth, skin-like sweetness. Bystanders often detect a stronger sillage than the wearer, whose receptors periodically saturate. A dry, clean base emerges.

After a few days+ d

Notable tenacity on fabric — detectable beyond 72 hours. On skin, a faint, warm, abstract woodiness persists. On blotter, substantivity exceeds 170 hours at full concentration. The residual trace is clean, dry, and nearly scentless to the adapted nose.

In PREMIEREPEAU

DISCOVERY SET7 × 2 ml →

The Full Story

Iso E Super (CAS 54464-57-2) is a synthetic woody-amber ketone, formally octahydro-tetramethyl-naphthalenyl-ethanone (OTNE). It is made via Diels-Alder cycloaddition of myrcene with 3-methyl-3-penten-2-one, followed by cyclization under phosphoric acid catalysis. The commercial product is not a single molecule but a mixture of isomers: approximately 30-65% beta-isomer, 8-20% alpha-isomer, and 10-33% gamma-isomer. The beta-isomer — the bulk of the mixture — is nearly odorless. The scent attributed to Iso E Super actually comes from a minor component called Arborone, present at only about 5% of the mixture, whose odor threshold is roughly 100,000 times lower than the beta-isomer's.

This isomeric reality explains the molecule's signature perceptual behavior: it fades in and out of awareness. The olfactory receptors that detect Arborone are thought to saturate rapidly, creating brief anosmia. When they reset, the scent reappears. The wearer loses it; bystanders catch it. The effect is a fragrance that seems to breathe — present, then absent, then present again — without any change in the composition itself.

In formulation, Iso E Super is used at widely varying levels. At 1-5%, it contributes warmth and roundness. At 10-30%, it becomes the primary architectural element of a composition, functioning as invisible scaffolding. It has high tenacity (172+ hours at full concentration on blotter). It is an ingredient in a large number of perfumes.

Pure Arborone remains difficult to produce at industrial scale via selective synthesis.

Sample every extrait in the Discovery Set.

Related notes: Amber · Ambergris · Ambrette · Ambroxan · Cashmeran · Cashmere · Cedarwood · Ebanol

Sources

Did You Know?

The beta-isomer that constitutes 30-65% of commercial Iso E Super is nearly odorless (threshold ~500 ng/L air). A minor component, called Arborone, present at only about 5%, has a threshold of ~5 pg/L — roughly 100,000 times more potent.

Extraction & Chemistry

Extraction method

Purely synthetic. No natural source exists. Produced via Diels-Alder cycloaddition of myrcene (a terpene obtained industrially by pyrolysis of beta-pinene from turpentine) with 3-methyl-3-penten-2-one, followed by intramolecular cyclization catalyzed by phosphoric acid. The reaction yields a mixture of positional isomers — alpha, beta, and gamma — in varying ratios depending on reaction conditions, catalyst loading, and purification steps. Industrial production is large-scale. The commercial product (typically 95-100% as the sum of isomers) is a colorless to pale yellow liquid with a specific gravity of 0.960-0.968 at 25 C.

Formula: C16H26O
CAS: 54464-57-2
Botanical: Synthetic (no botanical source)
Appearance: colorless to pale yellow clear liquid
Odour strength: Medium
Lasting power: 172 hours at 100.00%
Synonyms: OTNE ISO E SUPER

IFRA status

Restricted

Permitted. IFRA restricts Iso E Super (OTNE) to a maximum of 20% in Category 4 (fine fragrance applied to skin). Listed as a fragrance allergen in Annex III of the EU Cosmetics Regulation (entry 344, added by Regulation (EU) 2023/1545): labelling required above 0.001% in leave-on and 0.01% in rinse-off products. REACH registered.

Physical properties

Boiling point: 312.16 °C. @ 760.00 mm Hg (est)
Flash point: 232.00 °F. TCC ( 111.11 °C. )
Specific gravity: 0.96000 to 0.96800 @ 25.00 °C.
Refractive index: 1.49700 to 1.50200 @ 20.00 °C.

In Perfumery

Backbone material, diffusion enhancer, and texture modifier. Iso E Super provides a woody-amber foundation for a large number of fragrances. At low doses (1-5%), it lends warmth and smoothness without identifiable character. At high doses (10-30%), it becomes the dominant structural element — the load-bearing wall of the composition. It is used across a wide variety of perfumery products. In woody ambers, it is often the primary material by volume. In white florals, it extends sillage and smooths indolic sharpness. In citrus-aromatic compositions, it provides a warm landing in the drydown. It is a common ingredient in contemporary perfumery. Iso E Super also acts as a perceptual amplifier: compositions containing it project further and read as more layered than their formulas alone would predict. This is partly chemical (its vapor pressure and diffusion coefficient are well-suited to slow, steady evaporation) and partly perceptual (the fading-in-and-out phenomenon creates an impression of movement and complexity). At PREMIEREPEAU, Iso E Super contributes woody clarity and spatial diffusion to several compositions.

Role in the formula

01modifier

02signature note

03blender

04volume builder

05freshness

Available as

synthetic

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