( 32fi ) 



On treatment with dilute sulphuric acid the ketones were again 

 liberated from the carbazone. A liquid was obtained which appeared 

 to be optically inactive. Potassium permanganate still had a strong 

 action, therefore so much was added that the permanganate colour 

 no longer disappeared. If now a current of steam was passed through 

 the liquid, a colourless oil}' liquid distilled over with the water 

 vapours (m. p. 12^, Sp. Gr.^ 0.829, b. p..^^ 234°) which, on treatment 

 with semicarbazide, gave a compound melting at 124°. 



The elementary analysis led to the formula C,iHj,0, the propei-ties 

 mentioned quite agree with those of methyl-n. nonylketone (2-undeca- 

 none) the main constituent of the essential oil of Rata graveolens. 

 From the oxidised liquid could be isolated an acid which melts at 

 49° and has according to the analysis, the composition CjjH^gOs. 

 This proved to be 2-ketodecanic acid CH3.C0.(CHJ..C00H, which 

 on oxidation with chromic and sulphuric acids yielded suberic acid, 

 whereas on treatment with sodium hypobromite azelaic acid and 

 carbon tetrabromide were formed. 



CH3.C0.(CHJ..C00H -^^ COOH.(CH,),.COOH suberic acid 



NaO Bi- 



CH3.C0.(CH,)-.C00H -^ C()OH.(CH,)..COOH azelaic acid 



From the results obtained it follows that to the unsaturated ketone 

 must be attributed the formula: CH, ^ CH — (CH,), — CO.CH,. Il 

 is, therefore, nonylene-(l)-methylketone or undecene (1) one (10). 



As no separation of the semicarbazones from the ketones could be 

 effected by recrystallisation, another course was taken to isolate 

 the unsaturated ketone and it was endeavoured to convert it first 

 into a bromine addition product. Methylnonylketone however, is 

 attacked readily, with evolution of hydrogen bromide, when acted on 

 by a solution of" bromine in chloroform or carbon tetrachloride. On 

 the other hand a methyl-alcoholic solution of bromine ^) acts very 

 slowly on this saturated ketone. A solution of bromine in methyl 

 alcohol is, therefore, allowed to run into the mixture until the liquid 

 just assumes a yellow colour. The alcohol is distilled off and the 

 residue washed with sodium carbonate solution to remove traces of 

 hydrogen bromide. On now heating in vacuo at 160°, the saturated 

 compounds pass over, leaving the bromine addition product behind. 

 At 204°!- the greater portion of this distils as a colourless liquid 

 which, however, becomes dark on keeping. 



1) According to Lobry de Bruvn (B. 26, 272 [1893]) bromine acts very slowly 

 on methyl alcohol ; for this reason a methyl-alcoholic solution of bromine is much 

 to be preferred to an ethyl-alcoliolic one. 



