i 



ON THE CONSTITUTION OF CAMPHOR. 327 



Finally, whilst it appears unlikely that any simpler explanation than 

 that here suggested can be offered, the question clearly awaits further 

 investigation ; but it seems unlikely that the correct solution will be 

 obtained until the attention of investigators is directed to the examina- 

 tion of the points at which isomeric change probably occurs, since the 

 discovery of isolated facts in favour of either formula can only add to the 

 number of those already known, and can scarcely be regarded as conclusive 

 whilst strong evidence in favour of the other formula can be brought 

 forward. 



Addendum (^N'ovemher 3, 1900). 



The curious properties of lauronolic acid (2. a. ii.) may possibly be 

 accounted for by the occurrence of a change of structure similar to that 

 above suggested in the cases of /3-campholenic acid and isolauronolic acid, 

 and by applying a similar rule, the change might be represented 



CH„ 



I 

 CH, 



CMe . COOH CMe . COOH 



CMe., i CMe 



CHJ 



CH . COOH CMe 



Ca mphoric Acid. Lauronolic Acid. 



and the formula thus arrived at is in complete accordance with all that is 

 at present known of the properties of the acid, and on oxidation the acid 

 would be converted into a compound 



CMe . COOH 



I 

 CH2 CO. Me 



CH., 



\ 

 CO. Me 



which is, at the same time, a /3-ketonic acid and a 1 : 5-diketone, and 

 would therefore lose carbon dioxide readily, and suffer condensation in 

 alkaline solution, yielding a /3y-unsaturated ketone 



CHMe CHMe 



/\ /\ 



CH2 CO CH2 CMe 



II or I II 



CH.2 CH CH2 CH 



CMe CO 



with the properties of the laurenone obtained by Tiemann and H. Tigges ^ 

 on oxidising lauronolic acid with potassium permanganate. 



' Ber., 33, 2950. 



