This alcohol which is stereoisomeric with geraniol was found in 1902 in neroli oil3) in which it occurs principally as acetate. Furthermore, nerol has been found in the oils of petitgrain, rose, Mexican lignaloes and Helichrysum angustifolium. Synthetically it is obtained, together with geraniol and terpineol, by the action of acetic acid anhydride on linalool.4) It is likewise obtained in small amount (about 5 p. c.) upon the reduction of citral.
Nerol of unquestioned purity has not yet been obtained. The following constants were observed on a specially purified product:
B. p. 226 to 227° (755 mm.); 125° (25 mm.); d15o0,8813; aD + 0°.5)
1) Journ. f. prakt. Chem. II. 56 (1897), 28.
2) Tiemann, Berl. Berichte 31 (1898), 2899; Bouveault and Gourmand, Compt. rend. 138 (1904), 1699.
3) Hesse and Zeitschel, Journ. f. prakt. Chem. II. 66 (1902), 502.
4) Zeitschel, Berl. Berichte 39 (1906), 1780.
5) v. Soden and Treff, Chem. Ztg. 27 (1903), 897.
Nerol possesses an agreable, rose-like odor and in its chemical behavior reveals close similarity with geraniol. When shaken with dilute sulphuric acid, it readily yields terpin hydrate. Upon oxidation it yields either citral or an aldehyde that possesses the odor of citral. Like geraniol it is unstable toward formic acid at higher temperature. With calcium chloride it does not form a crystalline addition product, hence it can be separated, at least in part, from geraniol. A like separation may be affected by the diphenylurethanes because of their different solubilities in certain solvents such as petroleum ether and methyl alcohol.
Of its derivatives the tetrabromide1) melting at 118 to 119° and the diphenylurethane2) melting at 52 to 53° should be mentioned.