— 174 — 



On the subject of priority, Barbier and Grignard state in the last- 

 named publication that, although it is correct that we were the first to 

 prepare 1-pinonic acid by oxidising the 1-pinocamphone which occurs in 

 hyssop oil, yet we were only able to identify that substance at a later 

 date, after publication of Barbier and Grignard's first paper on the pre- 

 paration of active pinonic acids by the oxidation of pinene. 



These statements require correction. As will be seen from the note 

 in our Report of April 1908, p. 60, we definitely identified the keto-acid 

 obtained in the oxidation of pinocamphone as 1-pinonic acid before the 

 publication, in October of the same year, of the paper by Barbier and 

 Grignard which is referred to above. The identification took place by con- 

 verting the keto-acid into (also lasvorotatory) methoethyl heptanonolide; 

 from which, by combining it with an equal quantity of d-methoethyl hepta- 

 nonolide, we prepared the racemic compound. The further study of this 

 question, which we had expressly reserved to ourselves, has neither directly 

 nor indirectly been influenced by the researches of the two French chemists. 

 When we made known these investigations in October 1908 1 ), we only 

 found it necessary to observe that in the meantime other investigators 

 had likewise taken up the same subject. Barbier and Grignard, therefore, 

 are altogether mistaken when they speak of a repetition of their work by 

 us; this is quite out of the question. At the time when we published 

 the various investigations relating to the matter under discussion we ex- 

 pressly avoided using the word "priority", as in such a case as this it 

 is difficult to form a judgment on that subject, and we are, therefore, 

 the more surprised that Barbier and Grignard should now parade their 

 alleged claims to priority with so much ostentation. 



Vavon' 2 ), who had succeeded in hydrogenating turpentine oil by means of 

 platinum black and hydrogen, has repeatad the hydrogenation 3 ) with the frac- 

 tions of French, German 4 ), and American turpentine oil (« — 36° 9', + 14° 

 and — 1° for the yellow Hg-line) of which the b. p. lies between 155 and 

 165°. All these fractions gave a quantitative yield of the same hydro- 

 carbon, possessing the following constants: sol. p. — 45°, b. p. 166°, 

 df| 0,861, a from +23,8° to —23,8°. The author has arranged the ro- 

 tations of the different fractions before and after reduction into a scheme 

 of two parallel lines, and from mathematical calculations which we cannot 

 reproduce here, he concludes that all the turpentine oils examined by 



x ) We have not overlooked this paper, as Barbier and Grignard imagine; on the cont- 

 rary, an extended reference to it appeared in our Report April 1909, 120. But in this first 

 publication by Barbier and Grignard we fail to find any reference to our investigations of 

 April 1908. 



2 ) Compt. rend. 149 (1909), 997; Report April 1910, 166. 



3 ) Compt. rend. 150 (1910), 1127. 



4 ) It is not clear to us what the author means by "German turpentine oil" ; there only 

 exists German pine-tar oil, and this contains comparatively little pinene. 



