— 180 — 



through its brucine salt into its optically active component parts, a remark- 

 able synthesis, sylvestrene having not been prepared artificially before. 

 When magnesium methyliodide is allowed to act upon the ethyl ester of 

 d-l-methyl-zf-q/cZohexene-3-carboxylic acid (b. p. 143 to 144° [100 mm.]; 

 [«] D +66°), there is formed d-dihydrocarvestrenol (b. p. 108 to 111 , 

 at 30 mm). 



CH 3 



C C H 

 CH 2 /" ~N CH • C (CH 3 ) : CH 2 



CH 2 CH2 

 Sylvestrene. 



Although the alcohol is inactive, Perkin was able to convert it, by 

 treating it with hydrochloric acid, into sylvestrene (d-carvestrene) dihydro- 

 chloride, which was identical with a preparation obtained by Wallach, 

 thus proving the alcohol to be actually d-dihydrocarvestrenol. As, with 

 aniline, hydrogen chloride can be split off from sylvestrene dihydrochloride, 

 sylvestrene being formed in the process, the reaction described above 

 supplies the synthesis of this hydrocarbon. 



Caryophyllene. In the course of the examination of celery oil 1 ) 

 we had discovered an active sesquiterpene to which we had given the 

 name of selinene, the hydrochloride of which melted at 66 to 68°, after 

 repeated recrystallisation at 71 to 74°. As the properties of selinene 

 dihydrochloride showed a certain resemblance to those of caryophyllene 

 dihydrochloride, it appeared desirable to compare the two bodies and 

 their derivatives with one another. The investigation has shown the 

 hydrochlorides as well as the hydrocarbons to be altogether different. 



The published information concerning dihydrochloride of caryophyllene 

 is scanty, and the investigations which have been made are still partly 

 incomplete. Earlier investigators, such as Blanchet 2 ), and also Soubeiran 

 and Capitaine 3 ) have repeatedly described the genesis of a solid hydro- 

 chloride from copaiva balsam oil which, according to the subsequent dis- 

 coveries of Wallach, consists chiefly of caryophyllene, but these researches 

 agree only in very few points with each other. Wallach 4 ) obtained only 

 a liquid hydrochloride from the caryophyllene of clove oil. Schreiner 

 and Kremers 5 ), are so far the only investigators who have described in 

 detail the action of hydrochloric acid upon caryophyllene. At a low 

 winter-temperature ( — 30°) they obtained from the caryophyllene of clove 



!) Report April 1910, 33. 



2 ) Liebigs Annalen 7 (1833), 154. 



3 ) Ibidem 34 (1840), 321. 



4 ) Ibidem 271 (1892), 298. 



5 ) Pharmaceutical Archives 2 (1899), 296. 



