ThelLimonene Group of Terpenes. 
332 
Preparation . 38 
According to’Hempel, who compared the methods of Wiggers and De- 
ville, 8p. of turpentine oil are mixed with 2p. nitric acid (spec, gravity 
1.25—1.3) and 2p. alcohol. □ The mixture is shaken several times daily 
until crystals begin^to form. To obtain crystals in comparatively short 
time shallow dishes can be employed. The drained crystals are re-crys¬ 
tallized form alcohol. 
Terpineol. 
Synonyms: 
Terpineol 1 — List 2 1848. 
Berthelot 3 1852. 
Oppenheim 4 1864. 
Tilden 5 1878. 
Tanret 6 1885. 
Diterebenhydrat — Oppenheim 4 1864. 
Terpinhydrat — Flawitzky 7 1879 and 1887. 
Monohydrate de Terebenthene — Tanret 6 1885. 
Terpineol — ¥/allach 8 1885. 
Bouchardat and Voiry 9 1887. 
History: 
In an impure form, as so-called “ terpinol,” terpineol has given rise to 
manifold speculations, which need not be considered here. Both Tilden 5 
and Flawitzky, 7 according to opposite methods, obtained relatively 
pure terpineol, but it was Wallach who first introduced order into the 
chaos of older speculations. By means of a systematic study of the 
dehydration products of terpin, in which all side reactions were avoided 
as much as possible he ascertained that terpineol is the first dehydration 
product of terpin, and that by further dehydration it is converted, ac¬ 
cording to conditions, and reagents into one or more of three hydro¬ 
carbons, viz., dipentene, terpinene, terpinolene; also that in the process 
of dehydration of terpin small quantities of cineol are formed as 
byproduct. These few introductory remarks will enable us to interpret 
the older literature upon this subject. 
In 1846 Wiggers 10 obtained from terpin hydrate by heating the same 
with hydriodic acid a compound to which he assigns the formula 
C 20 H 16 + H. The results of his analyses do not at all agree well with 
this formula. He remarks that this substance might be regarded as the 
“Oxyd von einem aus dem Terpentinol neuentstandenen Radical = 
C 20 H, 17 wozu, aber, wie es scheint durchaus kein Grund vorhanden ist.’ 5 
22—A. & L. 
