98 
there was an ethylenic linking in it, like in camphor (I). According to Holz’), however, | 
this supposition does not agree with the facts, as there would be a ethylenic linking to ~ 
a tertiary hydrocarbon, which is common to two rings, and this is impossible for stereo- 
chemical reasons. The ketone rather contains a trimethylene ring. Holz replaced the 
oxygen in Angeli’s camphenone by hydrogen, following the method of Kishner2) and ~ 
Wolff*) and thus obtained an optically inactive hydrocarbon CioHis (m. p. 117 to 1189), — 
which distinguishes itself from camphane in that it contains a new ring linking in the 
molecule and two atoms of hydrogen less. Holz calls this hydrocarbon cyclocamphane (Il) 
and the corresponding ketone (Angeli’s camphenone), cyclocamphanone (Ill). After 
reduction with sodium and alcohol, cyclocamphanone affords a new borneol, -cyclo- 
camphanol, C,»HigO, melting between 174 and 176°. It resulted from the difference 
between the calculated and the established molecular refraction that there is no double 
linking in the molecule, but an exaltation of about 0,7 indicated the presence of a 
tricyclic ring. 
By splitting off water from the oxime of cyclocamphanone, the nitrile of cyclo- 
campholenic acid is obtained, which can be saponified with alcoholic potash lye to 
cyclocampholenic acid, CioHisO2 (IV), which through oxidation passes into cyclo- 
isocamphoronic acid, CyHi2O, (V), melting between 228 and 230°. The formation of 
the last-named acid conclusively proves the constitution of cyclocamphanone. 
G CH CH 
FC ht. aree Hee HCp>——_| cH 
| C(CH3)2 ccehih | C (CHa). 
Bae | 3533000 HCL | CH, AC ee 
C-CHs; C- CH; : C-CHs 
(1) Angeli’s formula for camphenone. (Il) Cyclocamphane, (Ill) Cyclocamphanone. 
CH * CH 
Fees Hc=———|— cH 
| C(CHs) | C (CHa) 
He te ee.e Hoek CO:H 
C-CHs; CO2H 
(IV) Cyclocampholenic acid. (V) Cycloisocamphoronic acid. 
Thujone. As is known, by isomerization of thujone, isothujone is obtained. This 
_ yields on reduction thujamenthol, which can easily be oxidized to thujamenthone. 
According to M. Godchot4), thujamenthone can be prepared in a simpler way by 
reducing thujone with hydrogen and nickel at from 175 to 180°. The thujone employed 
by him boiled at 199 to 201°; disc 0,9190; %  — 29,549; mp0 1,4546. The reduction 
product, thujamenthone, boiled from 207 to 209°; d2oo 08844; Np»0 1,4526. The semicar- 
bazone melted at 178 to 179°; the oxime, at 95°. Jsothujone likewise affords thuja- 
menthone on reduction with hydrogen and nickel. 
Wallach®) too reduced isothujone at the time and obtained thujamenthone, whereas 
thujone remained indifferent to the palladium atom charged with hydrogen. 
1) Zeitschr. f. angew. Chem. 27 (1914), I. 347. — *% Comp. Report April 1912, 195. — *) Liebigs Annalen ; 
394 (1912), 94; Report April 1918, 139. — 4) Compt. rend. 158 (1914), 1807, — 5) Liebigs Annalen 381 (1911), é 
85; Report April 1911, 165. , 
