— 190 — 



hydrolysed, giving rise to a dibasic acid (CioH 14 -C0 2 H)2S, contaminated ~ 

 with a neutral product. 



H 3 C-C:CH2 r^CiC-CHa 



HC CH 



HaCf^VcHa H 2 c/NCH 2 



CN-Clx JCH- S HCL JC-NC 



c c 



H 3 C CH 3 



In previous Reports (October 1906, 130, 131; November 1908, 186) we 

 have discussed the investigations of Rupe and Liechtenhan, of Klages and 

 Sommer, and of Rupe and Emmerich into the hydrocarbon methylmentha- 

 triene, which is generated by treating carvone with magnesium methyl 

 iodide. Rupe and Kerkovius 1 ) have further pursued these investigations 

 and have prepared a hydrocarbon of greater stability than methyl men- 

 thatriene, namely tetramethyl c^cZoheptatriene, which is readily obtainable 

 from eucarvone and magnesium methyl iodide. The first product is a ter- 

 tiary alcohol which gives off water at water-bath temperature and is con- 

 verted into the hydrocarbon. The latter forms a very mobile liquid, with 

 an odour reminding first of camphor and then of cajuput oil: b. p. 67 to 68° 

 (1 1 mm.), d 20 o 0,8687, n D20 o 1,50660. When reduced with alcohol and sodium 

 it yields tetramethyl q/c/oheptadiene. 



A modification of the process by allowing eucarvone and methyl iodide 

 to flow on to the magnesium, yields, in addition to the hydrocarbon, two 

 solid bodies, m. p. respectively 177 to 178° and 142 to 143°. These bodies 

 are probably stereomeric and represent dimolecular methylderivatives of 

 dihydroeu carvone. 



Phenols. 



Dicarvacrol. On p. 200 of our Report of October 1910 we referred 

 to dehydrodicarvacrol (dicarvacrol), a body which has been obtained by 

 Cousin and Herissey by acting with ferric chloride upon an aqueous 

 carvacrol solution. Since then, Cousin 2 ) has investigated the action of 

 bromine and chlorine upon dehydrodicarvacrol and has described a few 

 well-defined halogen-compounds. 



Oxides. I 



Cineole. G. Conn 3 ) has established that cineole combines with 1,5- 

 dihydroxy-naphthalene to form a double-compound which crystallises in the 



*) Berl. Berichte 44 (1911), 2702. 



2 ) Compt. rend. 154 (1912), 441. 



3 ) Pharm. Zentralh. 53 (1912), 32. 



