:j08 REPORT — 19(1(1. 



1. Oxidation of Camphor and Camphoric Acid. 

 (a) Oxidation with Nitric or Chromic Acid. 



When camphor is subjected to prolonged heating with nitric or 

 chromic acid a large number of products are obtained, of which the more 

 important are camphoric acid and its oxidation products, namely, cam- 

 phanic acid, camphoronic acid, and trimethylsuccinic acid, together with 

 a small quantity of isocamphoronic acid, which is certainly an independent 

 product, as it does not appear to be produced from camphoric acid under 

 any circumstances. 



(i.) Constitution of Camflwronia Acid. — From a study of the products 

 obtained ))y the dry distillation of camphoronic acid Bredt Avas led to 

 the view that this acid had the structure 



COOH . CMe2 . CMe(COOH) . CHg . COOH ^ 



and this conclusion has been rendered final by the synthesis of the acid 

 by Perkin and J. F. Thorpe - in a manner the course of which admits of 

 only one interpretation. 



(ii.) Constitution of Isocanvphoronic Acid. — Isocamphoronic acid has 

 the structure CMe2(C00H) . CH(CH2 . COOH).,, as follows from the 

 following observations : — 



When the acid is warmed with sulphuric acid it loses carbon 

 monoxide, and is converted into a lactonic acid of known constitution, 

 namely, terpenylic acid : 



CMeo . CH.CHo.COOH CMe., . CH.CH,.COOH 



I ' I ■ -> I I " +CO + H2O3 



COOH CH2.COOH O CH2 



\co/ 



Additional support for the formula given is supplied by the following 

 indirect observations : — 



a-Keto-isocamphoronic acid, obtained by a series of changes from 

 pinene, yields isocamphoronic acid when reduced, and when oxidised with 

 lead peroxide and acetic acid is converted into a-dimethyltricarballylic 

 acid. The latter acid is not a malonic derivative, and when treated 

 with bromine is converted into the lactone of the hydroxy-acid, M'hicli 

 yields a-dimethylsuccinic acid on fusion with potash : 



CMe2 . CH , CO . COOH CMe., . CH . CH, . COOH 



I I -> I " I 



COOH CH2.COOH COOH CH2.COOH 



o-Keto-isocamphoronic Acid. Isocamphoronic Acid. 



CMej . CH . COOH CMe2 . CH . COOH CMe, . CHj 



II -> I I -> I I 

 COOH CH2.COOH CO CH . COOH COOH COOH 



\o/ 



a-I)imethyltricarballylic Acid. Lactonic Acid. a-Dimethylsuccinic Acid. 



' £er., 26, 3049. ' Tra7ie. Chem. Soc, VI, 1169. » Tiemann, Bcr,, 29, 2612. 



