THE TERPENE GROUP 



CH 



trans-Terpin. cis-Terpin. Cineol, eucalyptol. 



Menthane is not a natural product. 



Menthol is the chief constituent of peppermint oil and can be made by 

 reducing menthone. 



Menthone is present in Japanese, American and Russian peppermint oil, 

 It exists in two optically active forms. 



Terpin is formed by the action of dilute acids upon the terpenes in tur- 

 pentine and upon other terpenes. 



Cineol is found in eucalyptus oil and is the anhydride of cis-terpin. 



Terpin easily forms a crystalline hydrate which melts at 117. 



Menthene Group, C 10 H 18 . 



CH 3 CH 3 



Dihydrocarvone. 



