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Technical Ingredient Overview
🏭 Manufacturer —Firmenich
🔎 Chemical Name — Undecanal
🧪 Synonyms — Undecyl aldehyde, n-undecyl aldehyde, aldehyde C-11 undecyclic
📂 CAS Number — 112-44-7
⚖️ Molecular Weight — 170.29 g/mol
📝 Odor Type — Aldehydic, floral, citrus
📈 Odor Strength — Medium to strong
👃🏼 Odor Profile — Sweet, waxy-fresh aldehydic character with prominent citrus-rose undertones and green floral nuances
⚗️ Uses — Floral and spicy compositions, citrus accords, rose complexes, aldehydic bouquets
🧴 Appearance — Colorless liquid
What is Aldehyde C-11 Undecylic?
Aldehyde C-11 Undecylic, chemically known as undecanal, is a saturated aliphatic aldehyde belonging to the homologous series of fatty aldehydes commonly employed in fine fragrance formulation. This eleven-carbon straight-chain aldehyde represents an important member of the aldehydic family that has been instrumental in creating the distinctive "aldehydic" character that defined classical perfumery throughout the 20th century.
The compound is characterized by its molecular formula C₁₁H₂₂O and features the characteristic carbonyl group (C=O) that imparts the sharp, radiant quality typical of aldehydic materials. As a member of the medium-chain aliphatic aldehydes (C₈-C₁₂), it occupies a strategic position in the olfactory spectrum, bridging the gap between the more volatile, citrusy short-chain aldehydes and the waxy, soapy character of longer-chain homologues.
Historical Background
The chemical discovery of aldehydes dates back to 1774 when Carl Wilhelm Scheele first synthesized acetaldehyde, but the complete understanding of aldehydic structures was not achieved until 1835, when German chemist Justus Freiherr von Liebig determined their constitution and coined the term "aldehyde" for this chemical group (R-CHO). Liebig's 1835 discovery of aldehydes represented a fundamental breakthrough in organic chemistry, laying the groundwork for future synthetic applications.
The transition from chemical curiosity to perfumery ingredient took several decades. Synthetic aldehydes were first successfully synthesized in 1903 by French chemist Auguste Darzen, opening the door for their practical application in fragrance composition. The first documented use of synthetic aldehydes in perfumery occurred in 1905 (some sources cite 1906) when French perfumer Pierre (Louis) Armingeat incorporated them into his reformulation of "Rêve d'Or" (Golden Dream) by L.T. Piver.
This pioneering aldehydic fragrance was followed by other early aldehydic compositions including "Quelques Fleurs" by Houbigant (1912), establishing aldehydes as a legitimate and desirable fragrance ingredient category. The systematic exploration of individual fatty aldehydes, including undecanal (Aldehyde C-11), gained momentum during the 1910s and 1920s as perfumers recognized their ability to provide lift, radiance, and sparkle to floral compositions.
Undecanal specifically gained prominence as one of the key aldehydic components in legendary fragrances, most notably as part of the aldehydic complex in Chanel No. 5 (1921), where it was used alongside other fatty aldehydes (C-10, C-12) to create the signature sparkling opening. By the early 20th century, aldehydes C-10, C-11, and C-12 had become essential tools for creating luminous, fresh, and sophisticated notes in modern perfumery.
The commercial availability of undecanal expanded significantly during the 1920s-1940s period as chemical manufacturers like Schimmel & Co. and later major fragrance houses developed reliable synthetic routes for its production. This period marked the true beginning of undecanal's role in defining the aldehydic floral category that became synonymous with sophisticated French perfumery.
Olfactory Profile
Scent Family: Aldehydic-Floral with citrus facets
Main Descriptors: The olfactory profile of undecanal is characterized by a distinctive sweet, waxy-aldehydic opening that quickly develops into bright citrus tones reminiscent of orange peel and mandarin zest.
Intensity: Medium to strong odor strength with excellent diffusion properties
Tenacity: Good longevity on blotter (6-8 hours) with moderate skin substantivity
Volatility: Medium volatility placing it in the top-to-middle note category, with excellent sillage properties
Fixative Role: Acts as a volume enhancer and radiance booster, particularly effective in lifting floral compositions and providing aldehydic sparkle
Applications in Fine Fragrance
Aldehyde C-11 Undecylic serves multiple roles in contemporary perfumery, primarily functioning as a radiance enhancer in aldehydic floral compositions. Its unique orange-rose character makes it particularly valuable in:
Aldehydic Florals: Essential for recreating the classic aldehydic bouquet effect, where it contributes to the sparkling, effervescent quality that characterizes this iconic fragrance family. Works synergistically with other aldehydes (C-8, C-9, C-10, C-12) to create complex aldehydic harmonies.
Rose Compositions: The natural rose facet in undecanal makes it an excellent companion to rose materials, where it provides fresh, dewy qualities that enhance the naturalness of both synthetic and natural rose components. Particularly effective with phenylethyl alcohol, rose oxide, and geraniol.
Citrus Accords: The prominent orange and mandarin characteristics allow for sophisticated citrus effects, especially when combined with natural citrus oils and other citrus aldehydes. Provides depth and complexity beyond simple citrus oils alone.
Floral Bouquets: Functions as a connecting bridge between different floral notes, particularly effective in white flower compositions where its green-floral aspects complement jasmine, tuberose, and narcissus.
The typical usage level ranges from 0.1% to 2% in finished fragrance, with most applications falling within the 0.5-1% range for optimal effect without overwhelming the composition.
Performance in Formula
Behavior in Blends: Undecanal demonstrates excellent blending characteristics with both synthetic and natural fragrance materials. It shows particular affinity for:
Other aliphatic aldehydes, creating complex aldehydic effects
Rose materials (phenylethyl alcohol, rose oxide, damascones)
Citrus oils and citrus-based synthetics
Green florals (leaf alcohol, violet leaf absolute)
Light musks and clean synthetics
Diffusion Characteristics: Exhibits strong radial diffusion with excellent projection, making it valuable for creating impactful openings in fragrance compositions. The material's volatility profile ensures good initial impact while maintaining presence through the early dry-down phase.
Impact on Overall Composition: Functions as an effective volume enhancer, capable of transforming flat floral compositions into radiant, three-dimensional structures. The material's dual aldehydic-floral character allows it to serve both as a top note contributor and middle note modifier.
Fixative Strength: While not a true fixative, undecanal demonstrates good substantivity and helps extend the longevity of more volatile citrus and green notes in the composition.
Compatibility: Shows excellent stability in alcoholic solutions and demonstrates good compatibility with most common fragrance solvents. No known incompatibilities with standard perfumery materials, though care should be taken with highly nucleophilic ingredients that might interact with the aldehydic functionality.
Industrial & Technical Uses
Beyond its primary application in fine fragrance, undecanal finds use in:
Flavor Industry: Applied as a flavoring agent in food products where its sweet, citrusy character contributes to orange and citrus flavor profiles. Usage is subject to FEMA regulations and typical food-grade purity standards.
Functional Fragrance: Employed in laundry detergents, fabric softeners, and household cleaning products where its fresh aldehydic character provides effective odor masking and pleasant scent impression.
Cosmetic Applications: Used in personal care products including shampoos, body washes, and skincare formulations where its fresh, clean character enhances the sensory experience.
Industrial Synthesis: Serves as a chemical intermediate in the synthesis of other aldehydic and related materials, though this represents a minor application compared to direct fragrance use.
Regulatory & Safety Overview
IFRA Status: Currently unrestricted under IFRA Amendment 51. No specific usage limitations or prohibitions identified in the current IFRA standards (verify current status at https://ifrafragrance.org)
GHS Classification: Classified as a skin sensitizer (Category 1) and may cause skin irritation. Eye irritant classification applies. Not classified as carcinogenic, mutagenic, or toxic to reproduction based on available data
EU Cosmetics Regulation: Permitted for use in cosmetic products when used within safe concentration limits. Not listed as a prohibited or restricted ingredient under Regulation (EC) No 1223/2009
Toxicology: Limited toxicological data available. Standard precautions for aldehydic materials apply, including proper ventilation during handling and skin/eye contact avoidance. Acute oral toxicity studies suggest low toxicity profile
FEMA Status: Status requires verification - not readily confirmed in public databases for food additive classification
Internal Links & Related Ingredients
This ingredient pairs excellently with other materials in the Scentspiracy database:
Aldehyde C-09 (Nonanal) - Complementary aldehydic character
Aldehyde C12 (Dodecanal) - Part of the classic aldehydic complex
Hydroxycitronellal - Excellent floral pairing
Cinnamic Aldehyde - Complementary aldehydic structure
For comprehensive understanding of aldehydic materials in perfumery, refer to the detailed article on Aldehydes in Perfumery.
References
Arctander, S. (1960). Perfume and Flavor Materials of Natural Origin. Elizabeth, NJ: S. Arctander.
Givaudan. (2024). Technical Data Sheet: Aldehyde C11 Undecylenic. Retrieved from https://www.givaudan.com/fragrance-beauty/eindex/aldehyde-c11-undecylenic
PubChem. (2024). Undecanal - Compound Summary (CID 8186). National Center for Biotechnology Information. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Undecanal
Sell, C. S. (2019). The Chemistry of Fragrances: From Perfumer to Consumer (2nd ed.). Royal Society of Chemistry.
Sigma-Aldrich. (2024). Undecanal 97% Product Information. Retrieved from https://www.sigmaaldrich.com/US/en/product/aldrich/u2202
This technical overview is compiled for fragrance industry professionals and has been curated by Scentspiracy's team of fragrance experts. All chemical data has been cross-referenced against authoritative sources including PubChem and industry-standard references.
Note: Regulatory status may change. Always verify current IFRA restrictions and local regulations before formulating. Some technical data points require further verification against proprietary industry databases not accessible through public sources.
