— 183 — 



has now himself entered the lists in this controversy. It would lead us too 

 far to go into details here on the subject of Komppa's rejoinder, and we 

 must therefore refer to the original paper. We need only mention here 

 that immediately after the publication of Blanc and Thorpe's article, 

 Komppa has again carried out his synthesis, with the result that he has 

 been able to confirm the statements which he made some time ago. 

 He is of opinion (and in our view justly so), that it would have been 

 better if Blanc and Thorpe had repeated his experiments in every detail 

 instead of making a long-established synthesis of fundamental importance 

 the object of attacks which are based upon very imperfect experimental 

 material, 



Many years ago Angeli and Rimini 1 ) observed that camphor oxime 

 and fenchone oxime, in ethereal solution, when allowed to react with nitrous 

 acid, form Ci Hi 6 N 2 O 2 compounds which, with concentrated sulphuric acid, 

 are converted into the same unsaturated ketone CioC^O. This ketone, 

 which they called "isocamphor", was afterwards identified as zl 6 -methyl-l- 

 ?sopropyl-5-q/cMiexenone-2 2 ). Mahla and Tiemann 3 ) having raised doubts 

 as to the identity of the ketones, Wallach 4 ) has repeated the experiments. 

 This investigation appeared to him to be all the more called for because 

 "isocamphor" is a metacymene derivative, and because it is important 

 to obtain a knowledge of this group of compounds on account of their 

 relationship with sylvestrene. Moreover, our knowledge of the reciprocal 

 relationship of the physical properties of hydrated and m-cymene compounds 

 is as yet very imperfect. 



Wallach has been able to confirm the results obtained by Angeli and 

 Rimini: The two isomerous nitrimines Ci Hi 6 N 2 O2 from fenchone oxime 

 and from camphor oxime, when reduced with concentrated sulphuric acid 

 yield the same ketone Ci Hi 6 O. It was by no means easy to determine 

 the physical constants of the ketone, because it resinified very readily. 

 The constants determined were as follow: b. p. 216°, d 20 o 0,9260, n D20 o 1,4758 

 mol. refr. 46,39, calc. for Ci Hi 6 O /T 45,82. The corresponding p-derivative, 

 carvotanacetone, gave the following constants: b. p. 228°, d 20 o 0,934 > 

 n D 1,4822, mol. refr. 46,41. The lowering of the m. p. due to the changed 

 position of the isopropyl, is particularly evident. 



The so-called "isocamphor" can be reduced, by treating it with sodium 

 in ethereal solution, to methyl-l-isopropyl-5-q/cfohexanol, which, when 

 oxidised with chromic acid and glacial acetic acid, forms methyl-1-isopropyl- 

 5-q/cfohexanone-2. The following table shows the constants of these bodies 

 and of their corresponding p-compound. 



9 Gazz. chim. ital. 26 (1896), II. 36. 



2 ) IMdem 30 (1900), I. 599. 



3 ) Berl. Berichte 29 (1896), 2819. 



*) Liebigs Annalen 379 (1910), 215. 



