— 134 — 



Camphor. Further detailed particulars concerning the total synthesis 

 of racemic camphor, which was first carried out by G. Komppa several 

 years ago are now available 1 ). Long ago the researches of Haller 2 ), 

 and of Bredt and v. Rosenberg 8 ), had described a process for the 

 conversion of active camphoric acid into active camphor, but the problem 

 still remained of converting Komppa's synthetic racemic camphoric 

 acid 4 ), by this process, into camphor. For this purpose the acid 

 (m. p. 202 to 203 ; «p io°) was converted into campholide by the 

 reduction of its anhydride (m. p. 220 to 220,5°). This campholide 

 melted at 211,5 to 2 12° and yielded bromocampholic acid (m. p. 178 

 to 1 79°). The cyanocampholic acid obtained by heating of campholide 

 with potassium cyanide was saponified to the corresponding homo- 

 camphoric acid (m. p. 231 to 232°), the calcium salt of which, when 

 subjected to dry distillation, was converted into racemic camphor with 

 a m. p. of 178 to 178,5°, this melting point not being reduced when 

 the substance was mixed with a preparation obtained by combination 

 of d- and 1-camphor. The oxime melted at 11 8°. Komppa has 

 also projected a total synthesis of. active camphor by the splitting-up of 

 racemic camphoric acid into its active components by the aid of quinine, 

 (by which process it has already been possible to produce pure 1-camphoric 

 acid,) or by splitting-up camphor itself over the corresponding borneols. 



Induced by this communication, E. Beckmann 5 ), has published 

 the result of experiments which were made by him, jointly with 

 E. Saran, as far back as in 1897. Isoborneol prepared by us 

 from camphene by Bertram's and Walbaum's process, only posses- 

 sed a rotation of a few degrees and consisted chiefly of a racemic 

 mixture, for the derivatives obtained from it (camphor m. p. 177 , 

 camphoric acid m. p. 200 to 202°, camphoric anhydride m. p. 219 

 to 220 ,) also rotated but very ieebly. For separation into the optic- 

 ally active component parts, the acid cinchonidine salt of camphoric acid, 

 melting at 196 to 198°, was employed. By fractionated crystallisation, 

 dextro and lsevorotatory camphoric acid, (m. p. 183°; Md -J- 44,4°; 

 and m. p. 186 to 187°, [«] D — 50,7° respectively) were obtained from 

 this. Besides the above, experiments were tried of separating the 

 isoborneol itself by fractional crystallisation of the cinchonidine salt 

 (m. p. 1 07°) of its acid succinate, but this process of decomposition 

 was only partly carried out. Afterwards, Pickard and Littlebury 

 succeeded in completely decomposing isoborneol by an analogous 

 process, with regard to which we made a communication at the time 6 ). 



*) Berl. Berichte 41 (1908), 4470. 



2 ) Compt. rend. 122 (1896), 446; 130 (1900), 376. 



3 ) Liebig's Annalen 289 (1896), 1. 



4 ) Berl. Berichte 36 (1903), 433^; Report April 1904, 98. 

 6 ) Berl. Berichte 42 (1909), 485. 



6 ) Comp. Report April 1908, 185. 





