Chemical Properties
Citronellol has a characteristic rose-like odor. Because odor plays such an important part in selecting this material,
there may be special grades of citronellol that do not meet the Essential Oil Association specification. These limits have been broadened
enough to include best qualities of commercial citronellol and chemically pure citronellol. l-Citronellol has a sweet, peach-like
flavor; d-citronellol has a bitter taste.
Chemical Properties
colourless liquid with a characteristic, rose-like, smell
Occurrence
l-Citronellol has been found in the plants of the Rosaceae family; d- and dl-citronellol have been identified in
Verbenaceae, Labiatae, Rutaceae, Geraniaceae and others; citronellol has been reported in about 70 essential oils and in the oil of
Rosa bourbonia; the Bulgarian rose oil has been reported to contain more than 50% l-citronellol, whereas East African geranium
contains more than 80% of the d-isomer; the natural product is always optically active. Reported found in guava fruit, orange, bilberry,
blackcurrant, nutmeg, ginger, corn mint oil (Mentha arvensis L. var. piperascens), mustard, pennyroyal oil (Mentha pulegium
L.), hop oil, tea, coriander seed, cardamom, beer, rum, and apple juice.
Definition
ChEBI: A monoterpenoid that is oct-6-ene substituted by a hydroxy group at position 1 and methyl groups at positions 3 and 7.
Preparation
By reduction of citronellal or geraniol or by fractional distillation of such essential oils as geranium and citronella (Bedoukian, 1967).
Aroma threshold values
Detection at 11 ppb to 2.2 ppm; l-form, 40 ppb
Taste threshold values
Taste characteristics at 20 ppm: floral, rose, sweet and green with fruity citrus nuances.
General Description
Citronellol is a volatile monoterpenic primary alcohol mainly found in the essential oil of plants such as Pelargonium graveolens, Cymbopogon winterianus and Rosa damascena. It is also one of the glycosidically bound aroma compounds in ginger.
Flammability and Explosibility
Nonflammable
Synthesis
It is generally accepted to distinguish rhodinol as the product isolated from geranium consisting of a mixture of l-citronellol
and geraniol, whereas the name l-citronellol should be used to indicate the corresponding synthetic product with the highest
level of purity; dl-citronellol can be prepared by catalytic hydrogenation of geraniol or by oxidation of allo-cyrnene; l-citronellol is
prepared from (+) d-pinene via (+) cis-pinene to (+) 2,6-dimethyl-2,7-octadiene and, finally, isolating l-citronellol by hydrolysis of the
aluminum-organo compound.
storage
4°C, protect from light
Purification Methods
Purify them bydistillation through a cannon packed (Ni) column and the main cut collected at 84o/14mm and redistilled. Also purify via the benzoate. [IR: Eschenazi J Org Chem 26 3072 1961, Naves Bull Soc Chim Fr 505 1951, Beilstein 1 IV 2188.]
