ChemicalBook > Product Catalog > Food Additives > Food flavorings > Artificial flavor > 3,7-Dimethyl-7-hydroxyoctanal
3,7-Dimethyl-7-hydroxyoctanal Chemical Properties
- Melting point:22-23 °C
- Boiling point:257 °C(lit.)
- Density 0.923 g/mL at 25 °C(lit.)
- FEMA 2583 | HYDROXYCITRONELLAL
- refractive index n
- Flash point:>230 °F
- storage temp. room temp
- form Liquid
- Specific Gravity0.93
- color Clear colorless
- JECFA Number611
- CAS DataBase Reference107-75-5(CAS DataBase Reference)
- NIST Chemistry ReferenceHydroxycitronellal(107-75-5)
- EPA Substance Registry SystemOctanal, 7-hydroxy-3,7-dimethyl- (107-75-5)
3,7-Dimethyl-7-hydroxyoctanal Usage And Synthesis
- DescriptionHydroxycitronellal has an intense, sweet, floral, lily-type odor. It may be prepared by hydration of natural citronellal obtained from Java citronella or from Eucalyptus citriodora; P-pinene is converted to myrcene, which on hydration may yield either linalool or a mixture of geranoil and nerol; the latter mixture can be hydrogenated to citronellol and subsequently converted to citronellal and hydroxycitronellal; also by hydrogenation of 3,7-dimethyl- 7-hydroxy-2-octen-2-al over palladium carbon in ethyl acetate solution.
- Chemical PropertiesHydroxycitronellal has a sweet, floral, lily-type odor
- Chemical Propertiesclear colourless liquid
- Chemical PropertiesThis is a colorless,
slightly viscous liquid with a floral odor reminiscent of linden blossom and lily of
the valley. Commercially available “hydroxycitronellal” is either optically active
or racemic, depending on the starting material used. Hydroxydihydrocitronellal
prepared from (+)-citronellal, for example, has a specific relation α20
D +9 to +10°.
Hydroxydihydrocitronellal is relatively unstable toward acid and alkali and is, therefore, sometimes converted into more alkali-resistant acetals, particularly its dimethyl acetal.
Because of its fine, floral odor, hydroxydihydrocitronellal is used in large quantities in many perfume compositions for creating linden blossom and lily of the valley notes. It is also used in other blossom fragrances such as honeysuckle, lily, and cyclamen.
- OccurrenceReported found in pepper
- PreparationThe most important synthetic routes to hydroxydihydrocitronellal
are listed as follows.
1) Synthesis from citronellal: One of the oldest routes to hydroxydihydrocitronellal is the hydration of the citronellal bisulfite adduct (obtained at low temperature) with sulfuric acid, followed by decomposition with sodium carbonate. A more recent development is hydration of citronellal enamines or imines, followed by hydrolysis.
2) Synthesis from citronellol. Citronellol is hydrated to 3,7-dimethyloctane-1,7- diol, for example, by reaction with 60% sulfuric acid. The diol is dehydrogenated catalytically in the vapor phase at low pressure to give highly pure hydroxydihydrocitronellal in excellent yield.The process is carried out in the presence of, for example, a copper–zinc catalyst; at atmospheric pressure, noble metal catalysts can also be used.
3) Synthesis from 7-hydroxygeranyl/-neryl dialkylamine: The starting material can be obtained by treatment of myrcene with a dialkylamine in the presence of an alkali dialkylamide, followed by hydration with sulfuric acid. The 7-hydroxygeranyl/-neryl dialkylamine isomerizes to the corresponding 7-hydroxyaldehyde enamine in the presence of a palladium(II)- phosphine complex as catalyst. Hydrolysis of the enamine gives 7-hydroxydihydrocitronellal .
- DefinitionChEBI: The tertiary alcohol arising from addition of water across the C2C double bond of citronellal.
- Taste threshold valuesTaste characteristics at 50 ppm: sweet, waxy, green, floral and melon notes.
- Trade nameLaurinal® (Takasago).
- Contact allergensHydroxycitronellal is a classical fragrance allergen, found in many products. It is contained in “fragrance mix.” It has to be listed by name in the cosmetics of the EU.
- Safety ProfileA skin irritant. Combustible liquid. When heated to decomposition it emits acrid smoke and irritating fumes. See also ALDEHYDES.
- Chemical SynthesisBy hydration of natural citronellal obtained from Java citronella or from Eucalyptus citriodora; β-pinene is converted to myrcene, which on hydration may yield either linalool or mixture of geranoil and nerol; the latter mixture can be hydrogenated to citronellol and subsequently converted to citronellal and hydroxycitronellal; also by hydrogenation of 3,7-dimethyl-7-hydroxy-2- octen-2-al over palladium carbon in ethyl acetate solution.
3,7-Dimethyl-7-hydroxyoctanal Preparation Products And Raw materials
- Company Name:Shanghai Jiulin Industrial Co., Ltd. Gold
- Company Name:J & K SCIENTIFIC LTD.
- Tel:400-666-7788 010-82848833-
- Company Name:Meryer (Shanghai) Chemical Technology Co., Ltd.
- Tel:400-660-8290 21-61259100-
- Company Name:Syntechem Co.,Ltd
- Tel:Please Email
- Company Name:BEST-REAGENT
- Tel:18981987031 400-1166-196