A sesquiterpene ketone derived from cedarwood oil. Acetyl cedrene delivers a dry, warm, woody-amber character with notable tenacity — a persistent base materials in the perfumer's kit. Neither sharp nor smoky, it provides a rounded cedarwood warmth that blends invisibly into almost any woody or amber base.
Dry, warm, unambiguously woody. The opening is clean cedarwood — not the sharp pencil-shaving bite of Atlas cedar, nor the smoky depth of Virginia cedar, but a rounded, polished version of both. An amber undertone emerges within minutes: soft, slightly sweet, with no vanillic heaviness. The effect is architectural rather than decorative — a structural warmth that other materials lean against.
On blotter, the drydown is notably stable. The woody-amber character persists with minimal evolution for days, eventually settling into a faint, clean, almost papery residue. On fabric, it can remain detectable for weeks. This linearity — a near-absence of development — is both its strength and its limitation: superb as a fixative scaffold, but requiring more volatile materials around it to create narrative.
Evolution over time
Immediately
Immediately
Dry cedarwood warmth, clean and rounded. A soft amber undertone appears immediately — no sharp edges, no smokiness. Quietly woody from the first moment.
After a few hours
After a few hours
The amber facet deepens slightly. The woody character becomes more papery and polished. Remarkable stability — the profile barely moves. A warm, neutral woodiness that simply persists.
After a few days
After a few days
Exceptional tenacity. A faint, clean, dry woody trace remains on blotter and fabric for weeks. No off-notes, no degradation — just a slow, graceful fade into a whisper of cedarwood.
The Full Story
Acetyl cedrene (CAS 32388-55-9) is produced by Friedel-Crafts acetylation of cedrene, itself obtained from cedarwood oil — primarily Texas cedarwood (Juniperus ashei) or Chinese cedarwood (Cupressus funebris). The starting material is abundantly available from sawmill waste, making the finished molecule inexpensive relative to its performance. The reaction yields a mixture of isomers; commercial grades typically contain ~80% of the target acetylcedrene isomer, with minor cedrene derivatives making up the balance.
Molecular formula: C₁₇H₂₆O. Molecular weight: 246.4 g/mol. The molecule sits on a tricyclic methanoazulene (cedrene) skeleton — structurally unrelated to Iso E Super, which is built on an octahydronaphthalene framework. The confusion between the two is common but incorrect: they share a woody-amber character zone but differ in skeleton, molecular weight (246 vs 234), CAS numbers, and odor profile. Acetyl cedrene is drier and more cedarwood-like; Iso E Super has a velvety, almost skin-like radiance.
The molecule was first described in the chemical literature in the mid-20th century as part of broader research into terpenoid modifications of cedarwood oil constituents. Its commercial significance grew from the 1970s onward as the fragrance industry sought cost-effective, high-tenacity woody base notes.
Regulatory note: Acetyl cedrene is classified as a fragrance allergen under Annex III of EU Cosmetics Regulation 1223/2009. Products containing it above 0.001% in leave-on formulations or 0.01% in rinse-off formulations must declare its presence on the INCI list. It does not carry an individual IFRA standard but falls under the terpenoid ketones group specification.
Acetyl cedrene is a tenacious materials in the perfumer's palette. A single application on a blotter can remain olfactively detectable for several weeks. On clothing, it routinely outlasts the wearer's memory of having applied it — which is why a favourite jacket can carry a phantom woody warmth months after its last encounter with fragrance.
Extraction & Chemistry
Extraction method: Friedel-Crafts acetylation of cedrene using acetic anhydride or acetyl chloride with a Lewis acid catalyst (typically aluminium chloride or zinc chloride). The cedrene starting material is isolated from cedarwood oil by fractional distillation. Commercial grades contain approximately 80% acetyl cedrene with minor cedrene-derived by-products. The process is straightforward industrial organic chemistry — no extraction from natural sources is involved. The molecule is entirely synthetic, though its precursor (cedrene) originates from natural cedarwood oil.
Molecular Formula
C17H26O
CAS Number
32388-55-9
Botanical Name
N/A (synthetic — acetyl cedrene)
IFRA Status
EU fragrance allergen (Annex III, Reg. 1223/2009). No individual IFRA standard; covered under group specification.
Structural base note and fixative. Acetyl cedrene extends the longevity of more volatile materials while contributing a clean woody-amber foundation. Typical usage: 3–15% in fine fragrance compositions. In fougères, it reinforces the woody base beneath lavender and coumarin. In ambers, it provides amber depth without the sweetness of benzyl benzoate or the heaviness of labdanum. In fresh compositions, it anchors citrus and green notes with a transparent woody platform that reads as clean rather than dense. Its cost-performance ratio is among the best in the palette: high tenacity, broad compatibility, low price per kilogram. This makes it a workhorse in both fine and functional fragrance (detergents, fabric softeners, candles). The molecule blends particularly well with Iso E Super, cedarwood oils, sandalwood, vetiver, and patchouli. Acetyl cedrene is sometimes confused with Iso E Super due to overlapping woody-amber character, but they serve different roles. Iso E Super has a velvety, skin-enhancing radiance; acetyl cedrene is drier, more traditionally woody, and significantly more tenacious.
