276 



SCIENCE PROGRESS 



carvone, on the other hand, gives rise 1 to an acid and an 

 aldehyde, the ring being split in the manner already defined : 



CH, + H 2 



CH 3 CH 2 



C 



I 

 CH . CH 2 . CO,H 



> / 



CH 2 



(acid C l0 H l8 O 2 ) 



n. 



CH 3 CH> 



C 



I 

 CH 



H 2 C 



H 2 C 



CH 2 



\ 



CHMe 



CH S CH, 



C 



I 

 CH 



H,C CH 2 .CHO 



(aldehyde, C 10 H l6 O) 



HC 



% 



CHMe 



Camphor 2 when exposed in aqueous alcoholic solution to 

 sunlight gives a mixture of campholenic aldehyde and a new 

 ketone isomeric with camphor itself. The action which occurs 

 is apparently as follows : 



CH, CH- 



■CH, 



CH 2 



I 

 CMe 2 



-CMe-^-CC 



CH a CH.CH,.CHO 



I 

 CMe 2 



I 

 CH = CMe 



Campholenic aldehyde. 



The formula assigned to the new ketone, from its behaviour 



on oxidation, is 



CHMe, 



I 

 CH 



HC 



CH., 



HC\/^CO 

 CHMe 



The ketone is the principal product. In this striking case of 

 isomeric change no hydrolysis appears to take place, the 



1 Atti R. Accad. Lincei, 1908, 17, i. 576 ; Ber. 1908, 41, 1928. 

 1 Atti R. Accad. Lincei, 1910, 19, i. 532. 



