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β-Dihydroionone (Dihydro Beta Ionone) Technical Ingredient Overview
🔎 Chemical Name — 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butanone
🧪 Synonyms — Dihydro-β-ionone; 7,8-dihydro-β-ionone; β-dihydroionone; alpha,beta-dihydro-beta-ionone; 2-butanone, 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-; dihydro-β-ionone DL
📂 CAS Number — 17283-81-7
📘 FEMA Number — 3626
⚖️ Molecular Weight — 194.31 g/mol
📝 Odor Type — Woody-floral with ionone character
📈 Odor Strength — Medium to moderate intensity
👃🏼 Odor Profile — Sophisticated woody-floral character with distinct violet and orris facets, complemented by warm ambery undertones and subtle fruity-berry nuances reminiscent of raspberry and peach. Softer and milder than parent β-ionone, exhibiting a smooth cedarwood quality with gentle mahogany-like depth and suede-like orris refinement (Givaudan, 2021; Leffingwell & Associates, 2023)
⚗️ Uses — Fine fragrance compositions (violet, orris, osmanthus, amber, and tobacco accords); trace flavoring applications in food products; cosmetic and functional perfumery for detergents, personal care, and air care products (Api et al., 2024; FEMA, 2025)
🧴 Appearance — Colorless to very pale yellow clear liquid
What is β-Dihydroionone?
β-Dihydroionone represents a saturated C₁₃ nor-isoprenoid ketone within the ionone family, a class of compounds that revolutionized modern perfumery when first synthesized in the late nineteenth century. This synthetic aroma chemical is produced through the catalytic hydrogenation of β-ionone, whereby the addition of hydrogen atoms to the side chain transforms the sharp, metallic violet character of the parent molecule into a gentler, more refined woody-floral profile (Lederer, 1949). The hydrogenation process softens the distinctive violet note while introducing a delicate cedarwood nuance and enhancing overall stability in fragrance formulations.
As a member of the ionone structural family, β-dihydroionone shares the characteristic cyclohexene ring system that defines this important class of perfumery materials. However, unlike α-ionone or β-ionone, which feature unsaturated side chains contributing to their intense floral-violet character, β-dihydroionone's saturated structure creates a more rounded, ambery-woody quality. This structural modification results in improved tenacity and substantivity, making it particularly valuable for building depth in modern floral and woody compositions (Boix Camps, 1999).
The compound occurs naturally in trace amounts within several botanical sources, most notably in Boronia megastigmaabsolute, osmanthus flowers (Osmanthus fragrans), certain raspberry varieties, and stone fruits such as peaches and apricots (Good Scents Company, 2021; BenchChem, 2025). These natural occurrences, while minimal, demonstrate β-dihydroionone's role in the complex aromatic profiles of flowers and fruits that have captivated perfumers for centuries.
Historical Background
The story of β-dihydroionone begins with the groundbreaking synthesis of the parent ionone molecules by German chemists Ferdinand Tiemann and Paul Krüger in 1893, working at the Haarmann & Reimer fragrance house in Holzminden, Germany (David, 2023). After seven years of intensive research, and with the assistance of terpene specialist Friedrich-Wilhelm Semmler, they successfully developed a method to synthesize ionones from citral and acetone through an intermediate compound called pseudoionone. This discovery fundamentally transformed perfumery by providing an affordable alternative to the prohibitively expensive violet flower absolute, which required 33,000 kilograms of violet flowers to produce just one kilogram of oil (Api et al., 2024).
The synthesis of β-dihydroionone emerged later as perfumers and chemists explored modifications to the original ionone structure seeking new olfactory dimensions. The selective hydrogenation of β-ionone to produce β-dihydroionone was achieved through the development of specialized skeletal nickel catalysts, with Chinese patent literature documenting optimized catalytic processes as early as 1999 (CN1212902A, 1999). This catalytic hydrogenation process became commercially viable through the work of major fragrance houses, particularly Givaudan, who recognized the material's unique ability to bridge floral and woody notes with exceptional stability.
Despite being synthesized relatively early in the twentieth century, β-dihydroionone remained an underutilized material for decades. Renowned perfumer Arcadi Boix Camps observed in 1999 that it was "a relatively old product that has only recently found a wider audience" following its prominent use in the creative accord of Issey Miyake's women's fragrance (Boix Camps, 1999). The material subsequently appeared in acclaimed fragrances including Dior's Dolce Vita, Bulgari pour Femme, and many others throughout the late 1990s and early 2000s, marking its transition from specialty ingredient to essential perfumery material.
Olfactory Profile
Scent Family: Woody-floral with ionone character; classified within the violet-orris-woody continuum
Main Descriptors: β-Dihydroionone presents a complex, multifaceted aroma that balances floral refinement with woody substantivity. The primary impression evokes violet blossoms and orris root, but softer and more diffuse than the sharp, candied violet of α-ionone or the intensely fruity character of β-ionone. The woody aspect manifests as smooth cedarwood with subtle mahogany undertones and a suede-like quality reminiscent of fine leather goods. Warm ambery facets emerge in the drydown, accompanied by delicate fruity notes suggesting raspberry, peach skin, and berry compote (Leffingwell & Associates, 2023; Givaudan, 2021).
The material exhibits what perfumers describe as "great beauty" despite its relative mildness—a sophisticated elegance that enhances rather than dominates a composition (Boix Camps, 1999). This quality makes it invaluable for creating naturalistic floral effects and adding dimensional depth to woody accords without the metallic or sharp edges sometimes associated with other ionone derivatives.
Intensity: Medium odor strength with excellent diffusion properties. While less powerful than β-ionone in terms of initial impact, β-dihydroionone offers superior tenacity and a more balanced evaporation profile that maintains presence throughout a fragrance's evolution (Givaudan, 2021).
Tenacity: High persistence with substantivity lasting more than twelve hours on a smelling strip and demonstrating excellent retention on both textiles and skin (Boix Camps, 1999). The compound exhibits good stability in various media, including alcoholic solutions, cream bases, and functional products.
Volatility: Medium volatility positioning β-dihydroionone primarily as a heart note with strong base note tendencies. With a calculated log P value of approximately 4.2, it demonstrates balanced lipophilicity that allows it to bridge the middle and base sections of a fragrance pyramid effectively (Api et al., 2024). This intermediate volatility makes it particularly useful for extending the heart note phase and providing smooth transitions between top and base notes.
Fixative Role: Functions as a subtle fixative, particularly in floral compositions where it helps anchor volatile notes while contributing its own olfactory character. The material enhances the longevity of more ephemeral floral materials such as rose absolute, jasmine, and citrus notes through both chemical synergy and its inherent substantivity.
Applications in Fine Fragrance
β-Dihydroionone occupies a distinctive position in the modern perfumer's palette, functioning as both a supporting player and a character note depending on concentration and context. Its primary application lies in creating sophisticated volume within floral compositions, where it adds roundness, depth, and a powdery-woody dimension that enhances the naturalness of flower recreations.
The material serves as an essential component in orris and iris reconstructions, where it works synergistically with α-ionone, methyl ionones, and irones to build the characteristic earthy-floral-woody profile of iris butter without the prohibitive cost of natural iris concrete (Boix Camps, 1999). In these accords, β-dihydroionone contributes the subtle woody-suede facets that distinguish authentic iris from simple violet.
Osmanthus reconstructions represent another crucial application, where β-dihydroionone combines with dihydro-β-ionol, γ-decalactone, and theaspirane to capture the apricot-floral-woody complexity of osmanthus absolute (Boix Camps, 1999). This accord has become increasingly important in modern perfumery, appearing in both feminine florals and unisex woody compositions.
In woody-amber fragrances, the material enhances diffusion and adds a sophisticated floral-fruity counterpoint to dominant woody notes from materials such as Iso E Super, cedarwood derivatives, and sandalwood. The ambery warmth of β-dihydroionone helps create seamless transitions between floral hearts and woody-amber bases, particularly when combined with ambergris accords, musks, and resinous notes.
Violet and powdery accords benefit from β-dihydroionone's ability to soften the sometimes strident character of α-ionone while maintaining violet recognition. The material brings a more natural, less candied violet effect that works particularly well in modern interpretations of classic violet themes.
Recommended pairings include combinations with Helvetolide, Tabanone, α-damascone, patchouli fractions, irone, allyl ionone, and pink pepper oil, where β-dihydroionone acts as a sophisticated bridge between diverse olfactory families (Boix Camps, 1999). The material demonstrates particular compatibility with rose materials, enhancing their complexity while adding woody depth.
Performance in Formula
β-Dihydroionone exhibits excellent stability across various fragrance bases and application types. In alcoholic perfume solutions, it maintains its character without significant alteration or degradation, making it suitable for eau de parfum and eau de toilette concentrations. The material demonstrates good solubility in typical perfumery solvents including ethanol, dipropylene glycol (DPG), and triethyl citrate (TEC).
In functional applications such as detergents and personal care products, β-dihydroionone shows moderate substantivity on both dry and damp substrates, contributing to lasting fragrance performance in laundry products, shampoos, and body lotions (Sigma-Aldrich, 2025). Its burning effectiveness rates as good, making it appropriate for use in scented candles and incense products where heat stability is required.
The material blends seamlessly with both natural and synthetic components, demonstrating particular synergy with floral absolutes, woody isolates, musks, and amber bases. Its medium volatility and balanced lipophilicity allow it to integrate smoothly into complex accords without creating harsh transitions or olfactory gaps.
Typical usage levels in fine fragrance range from 0.5% to 5% of the compound, though some compositions may employ higher concentrations when the material serves as a structural element rather than a supporting note (Boix Camps, 1999). In flavor applications, concentrations are significantly lower, typically not exceeding 10 parts per million due to the material's potency and the subtlety required in food flavoring (FEMA, 2025).
Industrial & Technical Uses
Beyond fine fragrance, β-dihydroionone finds application in functional perfumery including household products, personal care formulations, and industrial scenting applications. Its stability, moderate cost, and pleasant odor profile make it suitable for mass-market products where both performance and economics matter.
In the flavor industry, β-dihydroionone serves as a FEMA GRAS (Generally Recognized As Safe) flavoring substance, approved under FEMA number 3626 (FEMA, 2025). It contributes woody, fruity, and earthy notes to flavor systems, though its use remains limited compared to its perfumery applications due to its relatively subtle character and the availability of more cost-effective fruit flavoring materials.
The compound's natural occurrence in various fruits and flowers has prompted research into its biosynthesis pathways, particularly through carotenoid cleavage dioxygenase (CCD) enzymes and enoate reductase systems (BenchChem, 2025). These enzymatic routes offer potential sustainable production methods, though commercial synthesis via chemical hydrogenation of β-ionone remains the dominant manufacturing approach.
Regulatory & Safety Overview
IFRA Status: β-Dihydroionone is not individually restricted under the IFRA 51st Amendment standards (IFRA, 2023). The material may be used without specific concentration limits across all product categories, though responsible formulation practices should always consider cumulative exposure from multiple ionone-type materials in a single composition. Current IFRA documentation does not impose restrictions on β-dihydroionone for any category including Category 4 (hydroalcoholic and hydroglycolic products applied to recently shaved skin) where many aroma chemicals face limitations.
EU Cosmetics Regulation: Approved for use in cosmetic products under EU Regulation 1223/2009 without specific restrictions (European Commission, 2025). The material is not listed among the 26 fragrance allergens requiring mandatory declaration on cosmetic product labels, indicating its low sensitization potential relative to more reactive fragrance materials. The CosIng (Cosmetic Ingredients) database lists it under the INCI name "4-(2,6,6-trimethylcyclohex-1-en-1-yl)butan-2-one" with perfuming function designation.
FEMA Status: Designated as FEMA GRAS (Generally Recognized As Safe) under FEMA number 3626 for use as a flavoring agent (FEMA, 2025). The material has been reviewed by the Flavor and Extract Manufacturers Association Expert Panel and found acceptable for use in food applications at levels consistent with good manufacturing practices. Safety evaluation by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) supports its use in flavor applications (WHO Food Additives Series No. 42, 1999).
GHS Classification: Not classified as hazardous under standard usage concentrations according to Globally Harmonized System criteria (Sigma-Aldrich, 2025).
Toxicology: Research indicates β-dihydroionone possesses low acute toxicity with minimal sensitization potential under normal use conditions (Api et al., 2024). The RIFM (Research Institute for Fragrance Materials) safety assessment of mixed ionone isomers, which includes β-dihydroionone, confirms its safety profile for use in fragrance applications when employed according to industry standards. Studies have identified potential biological activities including antioxidant properties and possible anti-proliferative effects in certain cancer cell lines, though these findings require further research to establish clinical relevance (Smolecule, 2025). As with all organic compounds, direct skin contact with undiluted material may cause irritation, and concentrated vapors could irritate respiratory passages; however, these concerns are mitigated through proper formulation and dilution in finished products.
References
Api, A. M., et al. (2024). RIFM fragrance ingredient safety assessment: Ionone mixed isomers. Food and Chemical Toxicology, 186, 114545. https://doi.org/10.1016/j.fct.2024.114545
BenchChem. (2025). Dihydro-beta-ionone (CAS 17283-81-7). Retrieved from https://www.benchchem.com/product/b048094
Boix Camps, A. (1999). Perfumery: Techniques in evolution. Perfumer & Flavorist, 24(6), 1-12.
CN1212902A. (1999). Preparation of skeletal-Ni catalyst for selective hydrogenation of β-ionone to dihydro-β-ionone. State Intellectual Property Office of the People's Republic of China.
David, F., et al. (2023). Industrial fragrance chemistry: A brief historical perspective. European Journal of Organic Chemistry, 2023(41), e202300900. https://doi.org/10.1002/ejoc.202300900
European Commission. (2025). CosIng database entry: 4-(2,6,6-trimethylcyclohex-1-en-1-yl)butan-2-one. Retrieved from https://ec.europa.eu/growth/tools-databases/cosing/
FEMA (Flavor and Extract Manufacturers Association). (2025). Flavor Ingredient Library: 4-(2,6,6-trimethylcyclohex-1-en-1-yl)butan-2-one (No. 3626). Retrieved from https://www.femaflavor.org/flavor-library/dihydro-beta-ionone
Givaudan. (2021). Ingredient card: Dihydro-β-ionone. Technical documentation.
Good Scents Company. (2021). Technical data: Dihydro-β-ionone (CAS 17283-81-7).
IFRA (International Fragrance Association). (2023). 51st Amendment to the IFRA Standards. Retrieved from https://ifrafragrance.org/standards-library
Lederer, E. (1949). Studies in nor-isoprenoid chemistry. Helvetica Chimica Acta, 32, 2123-2124.
Leffingwell & Associates. (2023). Odor thresholds of ionone stereoisomers. Technical report.
OECD HPV. (2005). SIDS Initial Assessment Report for SIAM 20: Ionones. Organisation for Economic Co-operation and Development High Production Volume Chemicals Programme.
PubChem. (2025). Dihydro-beta-ionone (CID 519382). National Center for Biotechnology Information. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/519382
Sigma-Aldrich. (2025). Dihydro-β-ionone ≥90%, FCC, FG (Product No. W362603). Retrieved from https://www.sigmaaldrich.com
Smolecule. (2025). Dihydro-beta-ionone (CAS 17283-81-7): Properties and applications. Retrieved from https://www.smolecule.com/products/s588130
TCI America. (2025). Dihydro-beta-ionone >90.0% (GC) (Product No. D5751). Retrieved from https://www.tcichemicals.com
WHO. (1999). Safety evaluation of certain food additives and contaminants. WHO Food Additives Series No. 42. Joint FAO/WHO Expert Committee on Food Additives (JECFA), Fifty-first meeting.
