— 189 — 



occupies from 10 to 12 hours. In order to separate the camphenic acid 

 from the liquid which had been filtered off from the moist manganese 

 dioxide, the liquid was almost neutralised with hydrochloric acid and 

 evaporated to a small volume. The first body to crystallise out from the 

 solution diluted with soda was the sodium salt of camphenylic acid; 

 upon further evaporation a sodium salt of an acid with m. p. 138° was 

 separated out, the deliquescent camphenate of sodium remaining in solution. 

 The camphenic acid was liberated by hydrochloric acid; after being re- 

 crystallised from glacial acetic acid it appeared as snow-white granular 

 crystals, m. p. 135,5 to 136,5°. The yield from 1000 g. camphene was 

 640 g. In addition to the calcium, barium and copper salts, Aschan pre- 

 pared the ethyl ester, QoHuC^^Hs^, a liquid boiling at 141 to 142° 

 (5 mm.); d^ 1,0221; « D 4-0,18°; n 1,45368; mol. refr. 67,84, calc. 68,18. 

 These data, together with the indifference of the ester towards bromine 

 and towards permanganate of potassium solution rendered alkaline by soda> 

 show camphenic acid to be a saturated body. 



The camphenic acid itself was inactive. By oxidising 1-camphene 

 (Md — 90,3°) prepared from 1-borneol from pine-needle oil, Aschan obtained, 

 in addition to an inactive acid, a camphenic acid melting at 143,5 to 144°, 

 with sp. rot. — 1,88° (in 20% alcoholic solution). This is an isomeride of 

 the camphene-camphoric acid, m. p. 142°, described by Wallach 1 ). By 

 oxidising d-camphene of high rotatory power, which he had obtained from 

 the hydrochloride of d-pinene (from Greek oil of turpentine), Aschan pre- 

 pared d-camphenic acid: m. p. 143,5 to 144, [«] +1,87° (in 21% solution). 

 When mixed with an equal quantity of 1-acid, the result was the above- 

 described i-camphenic acid, m. p. 135,5 to 136,5°. 



Camphenic acid forms no anhydride. Like camphoric acid, camphenic 

 acid can be stereometrically transposed by heating with acids. Dry 

 distillation did not yield a uniform distillate, therefore no simple ketone 

 formation had occurred. The author was able, by applying special pre- 

 cautions, to brominate camphenic acid. In the course of this process, 

 monobromocamphenic acid, m. p. 189,5 to 190° (from 95% formic acid) 

 was formed. When treated with soda solution, monobromocamphenic acid 

 yielded dehydrocamphenic acid, CioH 14 4 , m. p. 155° (from water), as well 

 as a-hydroxycamphenic acid, C 8 Hi 3 (OH)(C0 2 H)2, m. p. 152°. Oxidation 

 of dehydrocamphenic acid with nitric acid gave rise to the lactone of 

 «,«-dimethyl-/?-hydroxyadipic-^-carboxylic acid, m. p. 256°, which, when 

 fused with potash, yielded a mixture of isobutyric and succinic acids. 



Hydropinene carboxylic acid. In the course of his continued 

 researches into hydropinene carboxylic acid and hydropinene aldehyde 2 ), 



■J Comp. Report October 1907, 138. 



2 ) Comp. Report April 1908, 177. Also comp. Report April 1906, 116; October 1906, 113. 



