— 135 — 



d 0,9290; n D 1,4803. This, however, when treated with hydrochloric 

 acid, does not yield back dipentene dihydrochloride, but terpinene 

 dihydrochloride (m. p. 5 2 ). The study of the constitution of this new 

 terpineol has not yet been completed. In addition to this terpineol, 

 there was discovered in the non- volatile products of conversion of 

 terpinene hydrochloride, a new terpin, which is more soluble than 

 its isomerides, and after crystallisation from acetic ester and ligroin 

 melts at 136,5 to 137,5°. But strange to say, there was also found both 

 ordinary cis- and trans-terpin. When the new terpin was treated with 

 glacial acetic acid and hydrobromic acid, it yielded terpinene dihydro- 

 bromide (m. p. 5 8°). The old terpin formula 



/CH 2 — CH 2 v 

 CH 3 -C(OH)< )C(OH)-C 3 H 7 



X CH 2 -CH/ 

 belongs to it. 



Wallach makes use of the previously mentioned dissimilar be- 

 haviour of terpinene and dipentene dihydrochlorides towards aqueous 

 alkali, in order to detect the two bodies alongside each other. Ter- 

 pinene hydrochloride, which resists the action of the alkali longer, 

 can, namely, be separated by fractional steam distillation from the 

 dipentene and a -terpineol formed from dipentene hydrochloride. 

 Wallach explains this behaviour thus, that the chlorine atoms in the 

 terpinene compound (comp. the formulae p. 134) are both situated in 

 the nucleus, and are consequently more firmly attached than the one 

 chlorine atom in the isopropyl group of the dipentene compound. 



By earlier studies of the constituents of Ceylon cardamom oil 

 (from long Ceylon cardamoms), carried out conjointly with E.Weber, 

 Wallach 1 ) had already demonstrated that this oil contains terpinene 

 and a terpineol not identical with ordinary terpineol. More recent 

 examinations 2 ), for which we again supplied the material, also showed 

 the presence of terpinene and a d-terpineol which yielded terpinene 

 dihydrochloride (m. p. 5 2°), the corresponding bromide (m. p. 59°), and 

 iodide (m. p. 76 ). In oil of sweet marjoram Wallach was also 

 able to detect this terpineol, in addition to a-terpineol already found 

 by Biltz 3 ). The new terpineol when treated with hydrohalogen acids 

 does not yield dipentene compounds, but gives a very good yield of 

 the above-described terpinene compounds. When oxidised with potassium 

 permanganate it yields a glycerol which, recrystallised from chloro- 

 form, forms needles melting at 114 to 11 6°; when heated carefully, 

 water separates off, and a product sublimes which melts at about 129 . 



*) Liebig's Annalen 238 (1887), 98. 



2 ) Liebig's Annalen 350 (1906), 168. 



3 ) Berl. Berichte 32 (1899), 995. 



