Sabinene 115

This hydrocarbon, which resembles ,B-pinene in some respects, has thus far been found in the oils of savin, Ceylon cardamom, marjoran and pilea. The following constants have been recorded:

B. p. 162 to 166°; d20, 0,840; aD +63°; nD 1,4661) B. p. 163 to 165°; d20o 0,842; aD + 67,5°; nD 1,4678.2)

1) Semmler, Berl. Berichte 33 (1900), 1464. 2) Wallach, Liebig's Annalen 350 (1906), 163.

In connection with the fractionation of a larger amount of sabinene from savin oil, Schimmel & Co. determined the following constants:

20%> boiling between 162 to 163°; d15o 0,8481; aD + 59°30'; 49°/o „ „ 163 „ 164°; „ 0,8480; „ +63°50';

31% „ „ 164 „ 165°; „ 0,8482; „ +-68°54'.

Significant is the low specific gravity which distinguishes sabinene from other hydrocarbons with a similar boiling point.

When boiled with dilute sulphuric acid, sabinene is converted into terpinene; with hydrohalogens the corresponding terpinene di-halogenhydrates result; when shaken with dilute sulphuric acid in the cold, sabinene yields active terpinenol-4 and terpinene terpin (see terpineol). The oxidation with permanganate is analogous to that of B-pinene. The resulting, sabinene glycol which melts at 54° and boils at 148 to 150° under 15 mm. pressure, has been used by Semmler for the identification of sabinene. Simpler, however, is the identification, according to Wallach, by means of the difficultly soluble sabinate of sodium which results upon oxidation in the presence of free sodium hydroxide.1) The free sabinic acid melts at 57°. Like nopinic acid it can be oxidized to a ketone C9H140, the sabinaketone, which likewise has served as a starting point for synthesis in the terpene group. The semicarbazone melts at 141 to 142°. When hydrogen chloride is passed into a methylalcoholic solution of sabinaketone, a mono-hydrochloride C9H150C1, m. p. 77 to 78°, results, whereas in glacial acetic acid solution a compound C18H29OCl3, m. p. 124°, is obtained. Sodium hypobromite oxidizes sabinaketone to thuja-dicarboxylic acid melting at 142 to 143°.