— H3 — 



But both are hardly attacked by oxidising agents; for this reason 

 the unobjectionable proof of their identity is difficult, and iso- 

 merism is not entirely excluded. Hesse summarises his experiments 

 in the following sentences: Pinene hydrochloride is bornyl chloride, 

 and has the same carbon skeleton as camphene hydrochloride. The 

 chlorine atom of the principal portion of the camphene hydrochloride must 

 be attached to the same carbon atom as that to which the chlorine 

 atom in pinene hydrochloride is attacked. Both hydrochlorides have 

 consequently an identical structure, and their differences can only be 

 explained by stereo-isomerism. Borneol which was abundantly obtained 

 from both hydrochlorides, and isoborneol obtained in larger quantities 

 only from camphene hydrochloride, are stereo -isomeric secondary 

 alcohols. On the much -debated question of the constitution of 

 camphene, Hesse's researches do not give a direct answer. The ex- 

 perimental part of the work contains in the first place the discussion of 

 the various reaction-products; next a detailed description of the production 

 of the pinene and camphene magnesium chlorides respectively, the action 

 of water on these, and the formation of inactive camphene from both; and 

 finally the oxidation - experiments with the two magnesium compounds. 

 In order to safeguard his priority respecting the synthesis of 

 borneol from pinene hydrochloride against Hesse, J. Houben 1 ) 

 reports on the production of borneol and bornyl acetate from pinene 

 hydrochloride. He obtains by his process up to 72 °/ of the theoretical 

 yield of borneol. Bornyl acetate he obtains by means of his method 2 ) 

 for the esterification of alcohols and phenols. 



Some new derivatives of pinene have been produced by 

 F. P. Leach 3 ) from pinene nitrosochloride. By treating the latter 

 with alcoholic potassium cyanate at 50 to 6o°, a compound C 12 H 17 3 N 3 

 (m. p. 238 to 240 ) can be isolated, which dissolves without decomposition 

 in hot concentrated nitric acid, and which by reduction with zinc and acetic 

 acid, with loss of C0 2 and NH 3 , forms the compound C 11 H 18 ON 2 

 (m. p. 2 2 4 ) which is also very stable. If the compound C 12 H 17 3 N 3 

 is treated with hot concentrated sulphuric acid, there is formed, with 

 loss of C0 2 and N H 3 , a base C 10 H 18 ON 2 (m. p. 123 to 125 ) 

 crystallising in needles. The body is amphoteric, and appears to 

 represent an amine oxime. This can also be obtained by simply al- 

 lowing NH 3 to act on pinene nitrosochloride. 



Limonene. We have already described the action of potassium 

 cyanide on limonene nitrosochlorides according to Til den and Leach 4 ). 



*) Berk Berichte 39 (1906), 1700. 



5 ) Berl. Berichte 39 (1906), 1736; comp. also the present Report, p. 120. 



*) Proceed. Chem. Soc. 22 (1906), 137. 



4 ) Journ. Chem. Soc. 85 (1904), 931; Report October 1904, 112. 



