io8 



oxidation this yields (though only in small quantity) the corresponding 

 ketone pinocarvone, C 10 H 14 O. The conversion from pinylamine 

 into pinocarveol is accomplished without ring -disruption, and the 

 fact that the grouping of the carbon atoms in both compounds is still 

 the same, is proved by the ready formation of cymene, for example 

 when boiling with aqueous sulphuric acid (i in 2). For pinocarvone 

 Wallach accepts the enolic form C 10 H 18 OH of a ketone with one 

 ethylene-linking. The ketone regenerated from the semicarbazone 

 (m. p. 204 ) boils at 95 (12 mm. pressure); d 0,984; n r>20° 1,5050; 

 the results agree with those previously obtained 1 ). The reduction of 

 pinocarvoxime (melting at 9 8°) in alcoholic solution with sodium 

 resulted in a base, b. p. 87 to 88° (12 mm. pressure), which differed 

 totally from pinylamine. The acid C 9 H 14 4 , b. p. 170 to 180 (12 mm. 

 pressure), formed by oxidation of pinocarvone with permanganate (1%), 

 melts at 96 to 97 , and is dibasic. Apart from its somewhat low 

 melting point, it resembles pinic acid in a remarkable manner. The 

 conversion into this acid is accomplished in the following manner: — 



CH 9 



CH, 



CH 2 



HON=C 



H 9 C 



/■' 



/ 

 CH £ 



CH 3 / 



1/ 

 C 



C H,NHC 



CH 2 



CH 



nitrosopinene 

 CH 



H C 



C HOHC 



/ \ 



CH 3 / 





1/ 





C 





/ 





CH 2 H 2 C 



CH 3 



/ 





\ 



/ 



CH 



pinylamine 



C 

 /\ 



CH 



CH 9 



CH 



pinocarveol 



OC 



H C 



/ 



CH 3 / 



1/ 

 C 



CH 



CH, 



\/ 

 CH 

 pinocarvone 



HOOC 



H 2 C 



COOH 

 \ 



CH 3 / 

 C 



/ 

 CH fi 



/ 

 CH 



pinic acid 



CH 



CH 



When pinylamine is treated with nitrous acid, a displacement of 

 the ethylene-linking takes place, which explains the constitution of 



1 ) loc. cit. 



