54 BACON. 



boiling between 80° and 83° at 40 millimeters pressure. It was redistilled over 



sodium at ordinary pressure, the final yield being 12 grams of oil of a boiling 



point 171° to 174°. The product is colorless, with an ethereal odor somewhat 



30° .30° 30° 



resembling that of benzene. Specific gravity, —^=0.8052, N'-T=r- = 1.4459, A—- 



=3.7. The analysis gave the following results: 



0.2037 gram substance gave 0.6397 gram CO, and 0.2602 gram H,0. 



Found Calculated for CioHoo 



(percent). (percent). 



C 85.64 85.72 



H 14.31 14.28 



This oil, Ci(,H„„, dissolves slowly in concentr.ated sulphuric acid (specific gravity 

 1.84) without warming or the evolution of sulphur dioxide, giving a slightly 

 reddish solution. The oil is recovered unchanged if the solution is quickly treated 

 with water, more prolonged action of sulphuric acid gives higher boiling products 

 containing sulphur. Concentrated sulphuric acid acts violently on limonene as 

 well as on its reduction product Ci„H]s, with marked resin formation and the 

 evolution of sulphur dioxide. Bromine reacts with CioH.„ by substitution, with 

 the evolution of hydrogen bromide. 



Sabatier and Senderson '^ reduced limonene with hydrogen in the 

 presence of niclcel sponge at 250° and thus obtained tetrahydro-limonene, 

 the p-methylisopropyl-C3fclohexane, CjoH,,,. 



CH. CH, 



CH 



1 

 CH 



H,C CH, 



I I 



CH 

 CH., 



This substance has a boiling point of 169° to 170° and a specific gravity 



0° 

 at j^ of 0.8133. However, this hydrocarbon was probably not pure, as 



the authors state, "accompagne d'une petite quantite des jiroduits de 

 deboublement et jjara dimethyl et para methyl ethyl cj'clo hexane." 

 Eenard '' obtained from resin oil a hexahydrocymol boiling between 171° 

 and 173° and having a specific gravity of 0.8116 at 17°. 



No doubt exists from the above experiments but that I have successively 

 jDassed from CioHnj through CjoHis to CjoHoj. An easy method of 

 obtaining tetra and hexahydrobenzene derivatives from terpenes and 

 their derivatives is therefore at hand. It might be questioned that a 

 compound of limonene hydrochloride with magnesium, obtained after the 



"C'ompt. rend. Acad. d. sc. Par. (1901), 132, 1256. 

 ^ Ann. Chim. Phys. (1884), (0) 1,230. 



