— no 



yielded on reduction with sodium and alcohol the same product of 

 hydration, i. e., a hydrocarbon C 10 H 18 with two double linkings, and 

 had the following constants: boiling point 166 to 168 (at 761mm. 

 pressure), n m7o 1,451, molecular refraction found 47,62, calculated 47,34. 

 The specific gravity of the dihydro-terpene from ocimene was 0,779; 

 the one obtained from myrcene was higher, namely 0,785, probably 

 owing to the presence of some unchanged myrcene. The identity of the 

 two products of reduction was further shown by the identity of the 

 tetrabromides of the melting point 88° produced from them. It is 

 therefore accepted as an established fact, that both ocimene and 

 myrcene are olefinic terpenes with three double linkings, of which 

 one can be saturated off by hydration, and the two others by the 

 addition of bromine. Different oxidation experiments with ocimene 

 yielded as characteristic compound malonic acid, and from this, as 

 also from the results of the redaction on the strength of Thiele's 

 views concerning the so-called conjugated double-linkings Enklaar 

 deduces for the two terpenes the following formulae: — 



CH/ 



CH 9 — CH 







CH, -CH, 



/ % 





CH 3X 

 CH 3 / 



/ \ 



C:CH C — 



CH 3 



:CH C 



/ 





/ 



CH 2 = CH 







CH 2 = CH 



Ocimene 



\ , 



/ 



Myrcene 





-4 1 

 CH 2 



-CH 2 





CH 3 v 

 CH 3 / 



/ 



\ 





: CH 



C — 



CH 3 





S 







CH a 



— CH 





Dihydroocimene (or dihydromyrcene). 



By hydration according to Bertram-Walbaum's method, there 

 was formed from myrcene the optically inactive alcohol C 10 H 18 O, 

 myrcenol, which Power and Kleber consider identical with linalool, 

 but which is thought to be different from the latter by Barbier, 

 Semmler and others. By comparison with the phenyl urethane of 

 linalool which was first produced in our laboratory 1 ), and which he 

 examined particularly for its optical activity, Enklaar demonstrated 

 that the two alcohols are different, although the melting points of 

 their phenyl urethanes lie only 2 to 4 apart. Myrcenol phenyl 

 urethane melted at 68°, the urethane of the optically active linalool 



x ) Report October 1902, 70. 



