82 ~ REPORT OF SCHIMMEL 8 Co. OCTOBER 1914/ APRIL 1915. 
Hydrocarbons. 
The synthesis of some hydrocarbons, allied to the terpenes, has been described 
by W. N. Haworth and A. W. Fyfe’). By condensing d-1-methyl-cyclohexane-3-one with 
ethyl cyanoacetate, they obtained /-1-methyl-4?- and -4°-cyclohexene-3-cyanoacetic acids 
and their ethyl esters. The elimination of carbon dioxide by the distillation of the 
cyano-acids leads to a mixture of d-1-methyl-4*- and -A*-cyclohexene-3-acetonitrile. The 
action of magnesium methyl iodide on these nitriles leads to d-1-methyl-3-acetonyl-A?- 
and -4*-cyclohexene, which distinguish themselves from one another by the solubility 
of their semicarbazones. By bringing together these ketones and magnesium methyl 
iodide, the authors obtained d-1-methyl-3-csobutanol-A?- and -d*-cyclohexene, from 
which d-1-methyl-3-dimethylvinyl-4?- and -A*-cyclohexene resulted by dehydration. The 
dehydration of d-1-methyl-3-isobutanol-4?-cyclohexene by means of potash hydrogen 
sulphate led to a hydrocarbon, which smells of limonene and presumably has a different 
- composition from the hydrocarbon obtained with the aid of oxalic acid. In the same 
manner A'-cyclohexene-1-acetonitrile was converted into 1-acetonyl-A*-cyclohexene, which 
with magnesium methyl iodide yields the terpene alcohol 1-zsobutanol-A*- cyclohexene 
(b. p. 106° at 17.mm.; d2 0,9258; m. p. of the phenylurethane — 105°), which under 
separation of water passed into the terpene 1-dimethylvinyl-4'-cyclohexene (b, p. 172 to 
Wace d= 0,8537; np 1,4854). In this case too, the dehydration by means of potash. 
disulphate led to a different hydrocarbon. 
Oxidation of hydrocarbons. 
As is known, only the unsaturated hydrocarbons are oxidized out of a mixture of 
unsaturated and saturated hydrocarbons, which latter are thus purified. N. Kishner’) 
studied this reaction more closely and found that it is a real induced reaction which 
takes place, as, in consequence of the oxidation of the unsaturated hydrocarbon, the 
saturated hydrocarbon is rather strongly attacked, which is not the case to such an 
extent with the pure hydrocarbon. 2,6-dimethyloctane f.i. is fairly stable when being 
boiled with potassium permanganate, but if menthene is added, the octane is likewise 
oxidized already at 50°. 
We made a similar observation at the time, when determining cineol with a 
potassium permanganate solution (comp. page 71). Pure cineol is scarcely acted upon 
in the cold by potassium permanganate, whereas in mixtures with easily oxidizable 
substances, such as terpineol, it is partly attacked. It is different as regards pinene, 
which is easily oxidized, but in the presence of cineol it becomes fairly stable against 
the action of potassium permanganate solution’). 
Isoprene. Some time ago we described an isoprene lamp, constructed by Harries 
and Gottlob*), with the aid of which only about 1 p.c. of pure isoprene were obtained 
from pinene, as against 50 p.c. from commercial carvene (limonene). At the time 
Harries and Gottlob supposed that the formation of isoprene from turpentine oil was 
due to the presence of dipentene. 
According to H. Herty and J. O. Graham‘), this idea is not correct, for when 
preparing isoprene from turpentine oil with the aid of the isoprene lamp, they obtained 
1) Journ. chem. Soc. 105 (1914), 1659. — 2) Journ.russ. phys. chem. Ges. 45 (1913), 1788; Chem. Zentralbl. 
1914, 1. 1498. — %) Report April 1918, 63. — +*) Comp. Report October 1911, 127. — 5) Journ. Ind. Eng. 
Chemistry 6 (1914), 803. : 
