124 RePoRT oF SciiMMiet,& Co. APRIL/OCTOBER 
intramolecular change the numeration of Bredt is (reed? The gene al 
which the work led are as follows: — | ote ee 
All substitutions in camphor took place in the methylene group 6, where 1 1 
hydrogen atom is easily replaceable. This fact, already discovered by Lipp’) in: 
camphor, was generally confirmed by Langlois in the bromine and chlorine deriva 
and in a new compound—methylol camphene. The camphene molecule, otherwise — 
prone to intramolecular change, became less capable of reaction by these substitutions. — 
Thus chloro-, bromo- and methyl camphene were unchanged on mixing a chromic 
acid, and also with hydrochloric acid in the cold. ast 
On oxidising with potassium permanganate, the substitution products vielen in” 
almost all cases, camphenilone (V), with rupture of the double bond, by which also the 
camphene nature of the compound was demonstrated. On the contrary, the compounds — “4 
with two camphene rings, as dicamphenilidene butane C.Mis: CH-CH2CH,CH:CoHis 
and bicamphenilidene diethyl ether CsHi,: CH-CHa-O-CH2CH: CoHis, are stable in the — 
presence of potassium pefmanganate, even on the water bath. Hence for the last 
A | = sip tia 
named an oxonium structure can be assumed CH-CH-CH: 0: CH-CH-CH. Yet even 
here also through gradual disintegration, first with chromic acid mixture, camphenilidene i 
acetaldehyde and camphene carboxylic acid can be obtained; and finally’ camphen tea ae 
by means of permanganate. 4 
In studying the halogen derivatives it became apparent that a camphene dichloride yam 
did not exist. Addition compounds could be obtained by the action of bromine and ~ 
chlorine on bromo- and chlorocamphene. Hydrogen bromide was added on, accompanied | 
by rearrangement which led to derivatives of the camphor type. = a 
The winning of dehydro dicamphene Cj5H,,: CH:CH: CoHis from bromocamphene, | 
and pentenyl camphene CyHi4: CH: CH: CaHs—a sesquicamphene — from camphenilidene 
acetaldehyde should also be noted. By condensation of camphenilidene acetaldehyde ~ 
with acetone the ketone CoHi,: CH-CH: CH-CO-CHs; was obtained, which was very ~ 
stable in the presence of chromic acid solution. This behaviour agrees with Thiele’s 
theory of the conjugated double bonds, and the mutually neutralising partial vale ee 
bch CH= ‘CH— C(CHs)= O. au 
ie 
harigmest the compounde described by Langlois are many isomerides with the con- / . 
stituents of sandalwood oil, and the disintegration products of santalol. . a 
Langlois used, as starting material, a camphene with the constants: — m. p. 429.8 
b. p. 158 to 160°; a) +58.2°. -bromocamphene CoHuCHBr (b. p. 225 to 226°; 
b. p. 115 to 120° [15 mm.]; dis. 1.265; «p) + 68.85°) was obtained by heating camphene 3 
dibromide with dimethylaniline to 180°. On passing chlorine into the ether solution Dy. 
of bromocamphene, bromocamphene dichloride (VI) [m. p. 74°] was produced; and on 
passing hydrobromic acid into bromocamphene he obtained the unstable camphene © 
dibromide CyoHisBr. (VII) [m. p. 90°], which, under the assumption of an internal : 
rearrangement.in opposition to Semmler*), he formulated as 2-bromo- co-bromocar a 
phane. On heating, it is decomposed into bromocamphene and hydrobromic aci 
The same camphene dibromide was obtained by passing bromine-free hydrochlor 
acid into a hot glacial acetic acid solution of bromocamphene. Eanglons asst 
= 
*) Cf. Report April 1914, 129. — *) Semmler reports that by the action of chlorine on cam 
compound C,oH;5;Cl- HCl is produced in addition to chlorocamphene CyoH,5Cl. Berl. Berichte 39 
— %) Cf. Berl. Berichte 33 (1900), 3426. 
