— 194 — 



/CH-COOH /CH-CO O CO-CH. 



C 8 H 14 <( | C 8 H 14 <( | | \c 8 H u 



\CH.OCOCH 3 x CH.OCOCH 3 CHgCOO-CH/ 



I. II. 



C 8 H 14 < || || )C 8 H 14 C 8 H 14 < I I )C 8 H 14 



III. IV. 



,C.COOH .C^— — COOH By oxidising bornylene 



c s H i4 \ L c s H i4 \ I ^ carboxy lie acid with perman- 



ganate, it was shown that 

 the unsaturated acid is acar- 

 boxylic acid of bornylene, 

 and not (as at first surmised) of camphene, and that the splitting-off 

 of water consequently takes place in a normal direction and without 

 rearrangement. This reaction yielded, in addition to camphoric acid (so- 

 luble in ether); hydroxy-oxide-camphane-carboxylic acid VI, 

 m. p. 208 to 209 , insoluble in ether. On the other hand, oxidation 

 with nitric acid only led to camphoric acid. As an unsaturated acid, 

 bornylene carboxylic acid united with hydrohalogens; its behaviour towards 

 hydrobromic acid was investigated closely, less closely that towards 

 hydrogen chloride. When treated with glacial acetic acid -hydrobromic 

 acid, the principal resultant product was /?-hydrobromo bornylene 

 carboxylic acid VII (/J-bromo-camphanic carboxylic acid) m. p. 90 

 to 91 , together with a compound called a hydroxy-acid, C n H 18 3 

 m. p. 169 . These bodies, owing to the sparing solubility of the 

 sodium salt of the brominated acid, were separable in cold con- 

 centrated soda solution. Nothing is reported as to the structure 

 of the supposed hydroxy-acid. It is not identical with any of. 

 the borneol carboxylic acids and therefore (as was proved by special 

 experiments) it cannot have been formed from the brominated acid 

 by the interchange of Br for OH. When its aqueous solution 

 was boiled with reflux - condenser this hydroxy-acid was converted 

 into a dehydrated acid, m. p. 55 , which volatilised with steam 

 and was an isomeride of bornylene carboxylic acid. The addition 

 of hydrogen chloride to bornylene carboxylic acid in a solution of 

 glacial acetic acid proceeds in analogous manner : besides the hydroxy- 

 acid mentioned already (m. p. 169 ) there is formed /?-hydrochloro- 

 bornylene carboxylic acid, m. p. 84 to 85 . But the action of 

 aqueous hydrobromic acid upon the unsaturated acid takes a different 

 course : in this case the chief product formed is a-brominated acid VIII 

 m. p. 1 57 with very little of the /S-brominated acid VII. The acid 

 with a high m. p. was recognised as a-bromo-substituted acid by the 



