3,7-Dimethyl-7-hydroxyoctanal Property

Melting point:

22-23 °C

Boiling point:

257 °C(lit.)

Density 

0.923 g/mL at 25 °C(lit.)

vapor pressure 

0.547Pa at 20℃

refractive index 

n20/D 1.448(lit.)

FEMA 

2583 | HYDROXYCITRONELLAL

Flash point:

>230 °F

storage temp. 

Inert atmosphere,Store in freezer, under -20°C

solubility 

Benzene (Slightly), Chloroform (Slightly), Methanol (Slightly)

form 

Liquid

pka

15.31±0.29(Predicted)

Specific Gravity

0.93

color 

Clear colorless

Odor

at 100.00 %. floral lily sweet green waxy tropical melon

Odor Type

floral

Water Solubility 

35g/L at 20℃

JECFA Number

611

Stability:

Air Sensitive

InChIKey

WPFVBOQKRVRMJB-UHFFFAOYSA-N

LogP

1.68 at 25℃

CAS DataBase Reference

107-75-5(CAS DataBase Reference)

NIST Chemistry Reference

Hydroxycitronellal(107-75-5)

EPA Substance Registry System

Octanal, 7-hydroxy-3,7-dimethyl- (107-75-5)

Safety

Hazard Codes 

Xi

Risk Statements 

38-41-43

Safety Statements 

26-39-36/37

RIDADR 

UN1230 - class 3 - PG 2 - Methanol, solution

WGK Germany 

1

RTECS 

RG7850000

HS Code 

29124990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H317May cause an allergic skin reaction

H319Causes serious eye irritation

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

3,7-Dimethyl-7-hydroxyoctanal Chemical Properties,Usage,Production

Description

Hydroxycitronellal 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 Properties

This 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.

Chemical Properties

clear colourless liquid

Chemical Properties

Hydroxycitronellal has a sweet, floral, lily-type odor

Occurrence

Reported found in pepper

Uses

Hydroxycitronellal is a fragrance for use in various perfumes, antiseptics, insecticides and household products; some perfumery uses (sweet pea Pois De Senteur; gardenia; cherry; melon; mint).

Uses

7-Hydroxycitronellal shows fungicide activity the strains of Candida tropicalis.

Definition

ChEBI: The tertiary alcohol arising from addition of water across the C2C double bond of citronellal.

Preparation

The 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 [151].

Taste threshold values

Taste characteristics at 50 ppm: sweet, waxy, green, floral and melon notes.

Flammability and Explosibility

Not classified

Trade name

Laurinal® (Takasago).

Contact allergens

Hydroxycitronellal 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 Profile

A skin irritant. Combustible liquid. When heated to decomposition it emits acrid smoke and irritating fumes. See also ALDEHYDES.

Synthesis

By 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.