- 175 — 



} In the course of the ozonising process acid and neutral decomposition 

 products were obtained. Among the former was a ketocarboxylic acid, 

 CnHisOs (b. p. 183 to 187° at 11,5 mm.; m. p. of the semicarbazone 183°), 

 and a diketocarboxylic acid C14H22O4 (b. p. 229 to 232° at 11,5 mm.). The 

 neutral decomposition products consisted of a ketone Ci Hi 8 O (b. p 73 to 

 76° at 11,5 mm.; m. p. of the semicarbazone 176°), a diketone Ci 2 H 2 o0 2 

 (b. p. 137 to 142° at 9 mm.; m. p. of the semicarbazone 219°) and a diketo- 

 aldehyde Ci 4 H 22 3 (b. p. 181 to 184° at 13 mm.). When oxidised with 

 nitric acid the ketocarboxylic acid CiiHi 8 3 yielded a dicarboxylic acid 

 C9H14O4, b. p. 222 to 225° (13 mm.) to which the authors give the name 

 of caryophyllenic acid. This body could not be obtained in the crystalline 

 form, and the attempts made by us, at Semmler's suggestion, to crystallise 

 the acid by strong cooling remained without result. Caryophyllenic acid 

 closely resembles pinic acid, but, unlike the latter, it yields an anhydride 

 (b. p. 152 to 158° at 10 mm.). The dimethyl ester of caryophyllenic acid 

 gives the following constants: b. p. 127 to 131° (11mm.), d 20 o 1,0456, 

 a D2oo+44°, n D20o 1,4462. In addition to caryophyllenic acid the oxidation 

 of the acid CnHisOs had yielded dimethyl succinic acid. The identical 

 products of oxidation are obtained when the keto acid is treated with 

 bromine solution. Semmler and Mayer conceive the generation of keto- 

 carboxylic acid from the ozonide to proceed as follows: — 



Terp.-Caryophyllene + Ozone 



C-CHo 



H 2 C 



COOH 



CH 2 CH 3 



Hypothetical intermediary product. 



CCH 



HN0 3 



Ketocarboxylic 

 acid. 



H 2 C 

 HC 



CCH 3 



COOH 



H 3 C-CCH B + 



COOH 



Caryophyllenic 

 acid. 



COOH 

 CH 2 

 H3C-C-CH 3 



1 



COOH 



Dimethylsuccinicr 

 acid. 



The diketocarboxylic acid Ci 4 H 22 4 was further oxidised with nitric 

 acid, when it yielded an oil studded with crystals which proved to consist 



