Title: Citronellal
CAS Registry Number: 106-23-0
CAS Name: 3,7-Dimethyl-6-octenal
Molecular Formula: C10H18O
Molecular Weight: 154.25
Percent Composition: C 77.87%, H 11.76%, O 10.37%
Literature References: Chief constituent of citronella oil; also found in many other volatile oils, such as lemon, lemon grass, melissa: Tiemann, Ber. 32, 834 (1899); Spoon, Chem. Weekbl. 54, 236 (1958). Structure: Naves, Bull. Soc. Chim. Fr. 1951, 505; Eschinazi, J. Org. Chem. 26, 3072 (1961).
Properties: Liquid. bp1 47°. nD20 1.4460. [a]D25 +11.50°. d 0.848-0.856. Soluble in alcohols; very slightly sol in water.
Boiling point: bp1 47°
Optical Rotation: [a]D25 +11.50°
Index of refraction: nD20 1.4460
Density: d 0.848-0.856
Derivative Type: a-citronellal
CAS Registry Number: 141-26-4
CAS Name: 3,7-Dimethyl-7-octenal
Additional Names: rhodinal
Properties: Liquid. bp1.4 51°. nD20 1.4410. [a]D20 +9.75°.
Boiling point: bp1.4 51°
Optical Rotation: [a]D20 +9.75°
Index of refraction: nD20 1.4410
Use: In soap perfumes; insect repellent.
Citrulline Citrullol Citrus Red 2 Cizolirtine Clanobutin

CAS number 106-23-0 YesY
PubChem 7794
ChemSpider 7506 YesY
EC number 203-376-6
KEGG C17384 YesY
ChEBI CHEBI:47856 YesY
Jmol-3D images Image 1
Image 2
Molecular formula C10H18O
Molar mass 154.25 g/mol
Density 0.855 g/cm3
Boiling point 201−207 °C
Related compounds
Related alkenals Citral


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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Citronellal or rhodinal or 3,7-dimethyloct-6-en-1-al (C10H18O) is a monoterpenoid, the main component in the mixture of terpenoid chemical compounds that give citronella oil its distinctive lemon scent.

Citronellal is a major isolate in distilled oils from the plants Cymbopogon,[2] lemon-scented gum, and lemon-scented teatree. The (–)-(S)-enantiomer of citronellal makes up up to 80% of the leaf oil from kaffir lime leaves and is the compound responsible for its characteristic aroma.

Citronellal has insect repellent properties, and research shows high repellent effectiveness against mosquitoes.[3] Research shows that citronellal has strong antifungal qualities.[4]