OP) CL 
26 REPORT OF SCHIMMEL & Co. OCTOBER 1914/ APRIL 1915, “7 
obtained. The authors succeeded in producing, in solid form, the ketone which had _ q 
been regenerated from the semicarbazone m. p. 237° with phthalic acid anhydride. — 
M. p. 43°; b.p. 163 to 166° (10 mm.); doo 1,017; «p + 123°; np 1,52700. Semmler and 
his collaborators assume that the gurjunene ketone possesses the empirical formula | 
CisH2.0, and not CisHesO, as indicated by Deussen and Philipp, although the molecular 
refraction, which shows a very big increment, really answers the formula C;;He,O better: 
calculated for Ci; H220/; 64,63, found 65,90. Increment 1,27. By reduction with sodium 
and alcohol the ketone yields gurjunene alcohol, Ci;Ho,O: m. p. 104°; b. p. 155 to 
159° (11 mm.); d 1,001; #p + 34° np 1,51859. 7 ea 
The ketone could not be reduced further. In the reduction of tricyclogurjunene 
with platinum and hydrogen only 2 atoms of hydrogen were added, tricyclodihydro- 
gurjunene being formed: b. p. 120° (8 mm.); d 0,9258; «» — 37,59; np 1,49775. Tricyclo- 
gurjunene may also be obtained from gurjunene ketone semicarbazone, by heating 
the setmicarbazone to 160° in a sealed tube with sodium alcoholate and alcohol. The 
hydrocarbon resulting from this method showed the same properties as the tricyclo- 
gurjunene, with the exception of the rotation which was found to be reduced. That, 
nevertheless, tricyclogurjunene, even though inverted, had been obtained was proved 
by the fact that in oxidizing with permanganate of potassium gurjunene ketone resulted 
once more. On heating gurjunene in the sealed tube to 290° only a slight inversion 
was noticeable. As is the case with all sesquiterpenes resembling cedrene, the 
tricyclogurjunene does not yield Turner’s colour reaction. By fractionated distillation 
of the crude gurjunene, a sesquiterpene of the following properties was obtained: 
b.p. 114 to 116° (10 mm.); doo 0,918; #) — 959; np 1,5010. This fraction consists of 
fairly pure tricyclenegurjunene (a-gurjunene). In the reduction it only adds two atoms 
of hydrogen; when oxidized it does not yield gurjunene ketone, but responds in a very 
pronounced manner to Turner’s colour reaction. By heating in a sealed tube complete 
inversion was attained. Neutral and acid bodies were obtained as oxidation products 
of tricyclenegurjunene, but nothing further is known about these bodies. 
In the reduction with platinum and hydrogen, crude gurjunene only adds 2 atoms 
of hydrogen, from which the authors conclude that it cannot contain any bicyclic 
sesquiterpenes. 
Hop Oil. In a very complete paper published by F. Rabak*) on hops and the 
relation between the composition of hop oil, and the hops used in its distillation, 
we find a few notes on the composition of hop oil. As constituents of this, oil 
dipentene, myrcene, linalool, isononylic acid (?), and humulene (a mixture of i-a- 
and $-caryophyllene) had been known so far, to which list Rabak now adds the follo- 
wing bodies: free formic acid (characterized by reduction of mercuric chloride to 
mercurochloride), heptylic acid (cenanthylic acid) (silver salt) and valeric acid (silver 
salt), esterified formic acid, acetic, decylic (caprinic), nonylic (pelargonic), octylic 
(caprylic), cenanthylic and butyric acids. In order to prove their presence, Rabak 
added little by little to the solution of the acid mixture, which had been neutralized 
with potassium hydroxide, a solution of nitrate of silver, carefully ascertaining the 
silver percentage of the precipitate after every addition. Formaldehyde was contained 
in the saponified oil (red coloration with Lebbin’s solution [a 5 p.c. solution of resor- 
cinol in a 40 to 50 p.c. solution of sodium hydroxide]). Besides myrcene and 
humulene, myrcenol also occurs in hop oil. Presumably it is present in the free 
1) Journ. of agricult. Research, Departm. of Agric., Washington, 2 (1914) 115. 
