Geraniol Fine 98%

• 🏭 Manufacturer — Symrise

• 📂 CAS N° — 106-24-1

• ⚖️ MW — 154.25 g/mol

• 📝 Odor Type — Floral Rosy

• 📈 Odor Strength — Medium

• 👃🏼 Odor Profile — Mild and sweet, floral Rose-type odor. Warm and yet slightly dry undertones, but there are great variations according to the quality and origin of the Geraniol.

• ⚗️ Uses — Although primarily a rose material, Geraniol is used generally as a sweet floral material of outstanding versatility. It forms convention- ally a major part of most artificial Ylang Ylang bases, and is often included in creations of Peony, Sweet Pea, Frangipani, Magnolia, etc.

WHAT IS GERANIOL?

Geraniol was first isolated in pure form in 1871 by the German chemist Oscar Jacobsen (1840–1889).

Using distillation, Jacobsen obtained geraniol from an essential oil obtained from geranium grass (Andropogon schoenanthus L.) produced in India. The chemical structure of geraniol was determined in 1919 by the French chemist Albert Verley (1867–1959).

In public use before the 1900s. Granted GRAS status by FEMA (1965) and is approved by the FDA for food use (GRAS). 

Geraniol occurs in many essential oils including rose, geranium, citronella, and palmarosa. In some instances, for example, some sources of palmarosa will comprise up to 90% of the oil. Nerol is less widespread; rose and palmarosa are the most important oils containing it. Both alcohols possess floral scents reminiscent of rose and hence are often referred to, along with linalool and citronellol, as the rose alcohols. (C. Sell)

Slightly soluble in water, miscible with alcohol and oils, soluble in Propylene glycol. it has a Mild and sweet, floral Rose-type odor. 

PRODUCTION METHODS

1. Dehydrogenation of geraniol and nerol is a convenient route for synthesizing citral, which is used in large quantities as an intermediate in the synthesis of vitamin A. Large-scale processes has, therefore, been developed for producing geraniol. Currently, these are far more important than isolation from essential oils. Nevertheless, some geraniol is still isolated from essential oils for perfumery purposes. 

2. Isolation from Essential Oils.
   Geraniol is isolated from citronella oils and from palmarosa oil. Fractional distillation of, for example, Java citronella oil if necessary after saponification of the esters present) yields a fraction containing ca. 60% geraniol, as well as citronellol and sesquiterpenes.
   A product with a higher geraniol content and slightly different odor quality for use in fine fragrances are obtained by fractionating palmarosa oil after saponification of the geranyl esters.

3. Synthesis from beta-pinene
   Pyrolysis of beta-pinene yields myrcene, which is converted into a mixture of predominantly geranyl, neryl, and linalyl chloride by the addition of hydrogen chloride in the presence of small amounts of catalyst, e.g., copper l) chloride and an organic quaternary ammonium salt. After removal of the catalyst, the mixture is reacted with sodium acetate in the presence of a nitrogen base e.g., triethylamine) and converted to geranyl acetate, neryl acetate, and a small amount of linalyl acetate. After saponification and fractional distillation of the resulting alcohols, a fraction is obtained that contains ca. 98% geraniol.

4. Synthesis from Linalool.
   A 96% pure synthetic geraniol prepared by isomerization of linalool has become commercially available. Orthovanadates are used as catalysts, to give a b90% yield of a geraniol ± nerol mixture. Geraniol of high purity is finally obtained by fractional distillation. A considerable portion of commercially available geraniol is produced by a modified process: linalool obtained in a purity of ca.65% from beta-pinene is converted into linalyl borates, which rearrange in the presence of vanadates as catalysts to give geranyl and neryl borates. The alcohols are obtained by hydrolysis of the esters. 

A LITTLE BIT OF HISTORY AND THE CONFUSION WITH IDENTIFICATION

Geraniol is an alcohol closely related to linalool but is distinguished from it by its optical inactivity and by its higher boiling point (linalool boils at 197 to 200, geraniol at 229 to 230). The conversion of linalool into geraniol was first observed by Barbier. This chemist found that the boiling point of linalool increases and its optical rotatory power decreases when it is heated with acetic anhydride at 120 for a long time; the resultant alcohol, having a rose-like odor, was thought to be different from geraniol, and was called " licarhodol." Bouchard at once expressed the opinion that this licarhodol was identical with geraniol. The correctness of Bouchardat's statement was conclusively proved by Bertramand and Gildemeister by the isolation of the calcium chloride compound of geraniol from Barbier's licarhodol. 

Geraniol is widely distributed in nature. Indian oil of geranium and palmarosa oil contains ninety-two percent, geraniol as shown by the experiments of Jacobsen and, more recently, by those of Semmler. 

It has also been found in pelargonium oil (African geranium oil) by Gintl, and in the oil of citronella by Schimmel & Co.

It occurs in the oil of Eucalyptus maculata, var. citriodora, and occurs, together with linalool, in lavender oil, lemongrass oil, and ylang-ylang oil. It is also found in small quantities in neroli and petitgrain oils, oil of spike, lignaloe oil, and sassafras oil. According to Smith, the oil from the fresh leaves and branchlets of Eucalyptus macarthuri contains sixty percent, geranyl acetate, 10.64 percent of free geraniol, as well as some eudesmol. 

Of especial interest, however, is the fact that the greatest part of the alcoholic constituents of Turkish and German oil of rose consists of geraniol (Bertram and Gildemeister ). 

In an investigation of the oil of rose, Eckart discovered an alcohol, C10H18O, to which he gave the name " rhodinol" Mark Ownikoff and Reformatzky examined rose oil and came to the conclusion that it contained an alcohol, C10H20O, which they Called "roseol". 

Barbier rejected the conclusion and confirmed Eckart's observations. Tiemann and Semmler further determined that rhodinal," C10H16O, which is obtained by the oxidation of Eckart's "rhodinol," C10H18O, is identical with geranial, C10H16O. The conclusive proof that rose oil contains geraniol was given by Bertram and Gildemeister by the isolation of the calcium chloride compound of geraniol from rose oil. More recent investigations have proved that rose oil and the ethereal oils of the genus Pelargonium contain geraniol, C10H18O, together with considerable quantities of another alcohol, citronellol, C10H20O. The terpene alcohol " réuniol" prepared by A. Hesse * from Reunion geranium oil by means of its camphoric acid ester, has been shown to be a mixture of Geraniol, C10 H18O, citronellol, C10 H20O. 

Erdmann and Huth suggested that the name "rhodinol" be substituted for that of geraniol; this suggestion, however, wasn’t accepted.

Barbier and Bouveault obtained an alcohol from the volatile oil of Andropogon sohoenanthus ; they considered it an individual chemical compound and called it " lemonol" Bertram and Gildemeister have proved that this " lemonol " is a mixture, containing considerable quantities of geraniol.

Very different opinions have been expressed from time to time by different chemists regarding the constituents of the abovementioned essential oils, and the nature of the alcohols obtained from them. The use of different names for geraniol and citronellol, or for mixtures of these two alcohols has led to considerable confusion in the study of these compounds and their derivatives. 

It must suffice here merely to note that the recent investigations, especially those of Bertram and Gildemeister, chemists of Schimmel & Co., Leipzig, have practically proved that geraniol, C10H18O, is identical with Lemonol (Barbier and Bouveault) and with "Rhodinol" (Erdmann and Huth, and Poleck) Citronellol C10H20O (Tiemann and Schmidt) is identical with " rhodinol " of Barbier and Bouveault and with "reuniol" (Hesse, Naschold); Eckart's "rhodinol" is a mixture of geraniol and citronellol, and the same be said of "roseol" (Markownikow); "licarhodol" (Barbier) is a mixture of about 85% of geraniol and 15% of dextro-terpineol. 

(this paragraph is entirely extracted from the chemistry of the terpenes heuslek-pond)

Sources and information

• A Fragrant Introduction to Terpenoid Chemistry, Charles S Sell, Quest International, Ashford, Kent, UK 

• Jacobsen, Oscar (1871). "Untersuchung der indischen Geraniumöls" [InvestIgation of Indian oil from geranium [grass]]. Annalen der Chemie und Pharmacie (in German). 157: 232–239.Jacobsen named geraniol on p. 234: "Danach ist dieser Körper, das Geraniol, isomer mit dem Borneol … " (Accordingly this body [i.e., substance], geraniol, is isomeric with borneol … )

• Semmler, F.W. (1906). Die ätherischen Öle [The Volatile Oils] (in German). Vol. 1. Leipzig, Germany: Von Veit & Co. p. 292. From p. 292: "Von dem Geraniol ist zu erwähnen, daß … erst Jacobsen (A. 157, 232) brachte im Jahre 1870 über den Alkohol, den er Geraniol nannte, nähere Angaben, er stellte die Formel C10H18O auf, ohne weitere Konstitionsangaben zu machen." (It should be mentioned about geraniol that … Jacobsen (A. 157, 232) first gathered in 1870 more detailed data about the alcohol, which he named geraniol ; he established its [empirical] formula C10H18O, without providing further data about its chemical structure.) See also: § 49. Geraniol C10H18O, pp. 439-493. On p. 439, two hypothetical structures of geraniol are proposed.

• (Semmler, 1906), p. 491.

• Verley, Albert (1919). "Sur la constitution du géraniol, du linalool et du nérol" [On the chemical structure of geraniol, linalool, and nerol]. Bulletin de la Société Chimique de France. 4th series (in French). 25: 68–80. The chemical structure of geraniol appears on p. 70.

• Common Fragrance and Flavor Materials, Preparation, Properties and Uses Fourth, Completely Revised Edition, Kurt Bauer, Dorothea Garbe, Horst Surburg