GREENS, HERBS AND FOUGERES / green · violet · fruity
Undecavertol
Category
GREENS, HERBS AND FOUGERES
Subcategory
green · violet · fruity
Origin
Volatility
Top Note
Botanical
N/A — synthetic molecule (no natural source)
Appearance
Pale yellow to yellow clear liquid
Odor Strength
medium
Producing Countries
Synthetic — manufactured worldwide
Pyramid
Top
Crushed violet leaves on a wet garden path, but colder and cleaner than the absolute — a dewy metallic green with no wax, no warmth. Undecavertol is a synthetic allylic alcohol (4-methyldec-3-en-5-ol, CAS 81782-77-6) engineered to isolate the transparent, rain-washed quality of violet leaf while discarding its heaviness.
Immediate impression: cold, wet greenness — the underside of a violet leaf pressed between wet fingers. A metallic sheen sits over the green, closer to the mineral flash of crushed stems than to any floral sweetness. Drier and sharper than violet leaf absolute, which carries a waxy, slightly animalic underbelly that undecavertol deliberately omits. Less resinous than galbanum, which has an incense-like heft. Less aggressive than methyl 2-octynoate, which can turn abrasive in overdose. As the molecule settles, a faint fruity-floral layered surfaces — a trace of unripe pear peel, barely detectable. The dry-down is clean, faintly soapy, with a woody-green whisper. On a blotter, the metallic edge fades by hour two; the clean green residue holds for a full day.
Evolution over time
Immediately
Immediately
Cold metallic green burst. Wet violet leaf, crushed stems, a mineral flash. The green is transparent and angular — no warmth, no sweetness. Faintly reminiscent of unripe melon rind but sharper.
After a few hours
After a few hours
The metallic edge softens. A clean, slightly soapy green-floral quality emerges — woody undertones surface, with a trace of unripe pear peel. The violet-leaf character becomes more rounded, less aggressive. Still clearly green but warmer.
After a few days
After a few days
On blotter at 24 hours: a faint, clean, woody-green residue. Soapy and dry. The distinctive violet-leaf character is no longer identifiable as such — what remains is a generic clean-green ghost. Effectively spent by 31–36 hours at full concentration.
The Full Story
CAS 81782-77-6. IUPAC name: 4-methyldec-3-en-5-ol. Molecular formul a C₁₁H₂₂O, molecular weight 170.29. An allylic alcohol — the hydroxyl group sits adjacent to a trisubstituted carb on-carb on double bond between C-3 and C-4. The 11-carb on cha in, the unsaturati on, and the methyl branch at C-4 together produce a scent profile that reads as green, violet-leaf, and faintly metallic: a synthetic distillati on of the dewy, rain-on-leaves quality of violet foliage, stripped of the waxy, phenolic heaviness that makes the natural absolute challenging to dose.
Structure and Stereochemistry
The molecule contains two elements of stereoisomerism. The double bond at C-3/C-4 can adopt E or Z geometry, and C-5 (bearing the hydroxyl) is a chiral centre. This gives rise to four possible stereoisomers, each with a subtly different olfactory character. Whether the commercial product is sold as a single isomer, an enriched mixture, or a statistical blend is proprietary information. The SMILES notation (PubChem CID 163336) is CCCCCC(C(=CCC)C)O, representing the unresolved stereochemistry.
Physical Properties
Pale yellow to colourless liquid. Boiling point: 255–256°C at 760 mmHg. Flash point: 97.8°C (208°F TCC). Specific gravity: 0.842–0.847 at 25°C. Refractive index: 1.452–1.459 at 20°C. LogP: 3.9 (estimated). These values place undecavertol in the moderately lipophilic range — less volatile than cis-3-hexenol (the classic green-leaf molecule, BP 157°C), substantially more persistent than low-molecular-weight aldehydes used in green accords.
Perfumery Context
Undecavertol belongs to a small family of synthetic green molecules designed to approximate specific qualities ofviolet leaf absolute without its complications. The natural absolute (Viola odorata, CAS 8024-08-6) is expensive, variable between harvests, and carries heavy waxy fractions that can muffle a composition. Synthetics like undecavertol offer the perfumer a scalpel where the absolute offers a hammer.
The name is a constructed portmanteau: undeca (Latin for eleven, referencing the 11-carbon chain) + vert (French for green, describing the odour character) + ol (the IUPAC suffix for alcohols). It is a captive molecule — a proprietary ingredient available only from its originating manufacturer, not sold on the open market. Captive status restricts its use to perfumers working with that supplier’s palette.
Substantivity is 31 hours at 100% concentration (TGSC data), which is high for a green material. For comparison: cis-3-hexenol persists roughly 6–8 hours, and galbanum resinoid lasts considerably longer but brings an entirely different character (resinous, incense-like). Undecavertol’s moderate tenacity means it bridges the top-to-heart transition without vanishing after the first hour — a structural advantage in compositions where the green note needs to hold through the mid-register.
Undecavertol has two sources of stereoisomerism: a chiral centre at C-5 (the carbon bearing the hydroxyl group) and an E/Z geometric isomerism at the C-3/C-4 double bond. This means the commercial material is potentially a mixture of up to four stereoisomers, each with a slightly different odour profile. The ratio of isomers in the commercial product — and whether the supplier sells a specific isomer or a mixture — is proprietary information.
Extraction & Chemistry
Extraction method: Fully synthetic. No natural source exists — the molecule does not occur in nature in isolable quantities. Undecavertol (4-methyldec-3-en-5-ol) is manufactured via industrial organic synthesis. The exact commercial route is proprietary. General approaches to allylic alcohols of this type involve base-catalysed aldol condensation or organometallic addition of a vinyl Grignard reagent to a suitable aldehyde. The molecule has 11 carbons, one hydroxyl group, and one trisubstituted double bond (C-3/C-4). It is a captive ingredient — available exclusively from its originating manufacturer.
Molecular Formula
C₁₁H₂₂O (MW 170.29) — 4-methyldec-3-en-5-ol
CAS Number
81782-77-6
Botanical Name
N/A — synthetic molecule (no natural source)
IFRA Status
No restriction under the IFRA 51st Amendment (2023). Undecavertol is not listed as a restricted, prohibited, or specified ingredient. Individual batch purity and allergen content should be confirmed with the supplier.
Top-to-heart modifier, positioned in the green-fresh register. Undecavertol provides controlled violet-leaf character without the waxy density or batch variability of the natural absolute. Its advantage is precisi on: it delivers the dewy, metallic-green quality of Viol a odorat a foliage at exact concentrations, without carrying the heavy, slightly phenolic undertones that make violet leaf absolute difficult to dose. Functionally, undecavertol is a lifting agent and blender. It pushes green accords into sharper focus, adds vegetal freshness to white florals, and sharpens citrus openings with a leafy counterpoint. It sits comfortably in chypre constructions (bridging bergamot and oakmoss), in green-floral hearts (alongside galbanum, cis-3-hexenol, and hedione), and in modern aquatic-green compositions where clean transparency matters more than naturalistic complexity. The molecule is a captive — a proprietary creati on available only from its originating supplier. This lim its its use to perfumers with access to that supplier's palette, which partly explains why undecavertol appears in a relatively narrow range of commercial formulations despite its technical usefulness. Key comparisons: drier and more metallic than violet leaf absolute; less aggressive than methyl 2-octynoate (methyl hept in carbonate); greener and less resinous than galbanum; less waxy than cis-3-hexenyl salicylate. Substantivity is moderate at 31 hours (TGSC, 100% concentrati on), giving it genuine heart-note presence — unusual for a green material. No confirmed presence in the current Premiere Peau collecti on.
