— i6o — 



purification of the crude fenchone with nitric acid, owing to oxidation 

 of the 1-borneol or its esters present in the oil. 



In the d-fenchone of fennel oil, Wallach was also able to state 

 the presence of d-camphor. Whether the latter is contained in the 

 oil as such, or is only formed by oxidation of the borneol or camphene 

 detected in the fennel oil, is a question which cannot be settled 

 without further experiments. 



In order to determine the molecular weight of some anorganic 

 compounds, E. Rimini and F. Olivari 1 ) have employed fenchone, 

 which readily dissolves various elements and salts, and is suitable for 

 exact measurements, as an ebullioscopic solvent. In an ordinary 

 Beckmann's apparatus with a china-ware jacket the authors have determ- 

 ined for pure fenchone (b. p. 192,5°) the constant k on the average at 

 59,4, a value which stands very close to that of menthone (k=62,5) 

 and of camphor (k = 58,5). 



Menthone. Haller and Bauer 2 ) had vainly endeavoured to 

 arrive by the action of Grignard's salts on ethyl camphor, at bodies 

 of the formula (I.), and attributed the absence of the reaction to a 

 steric impediment. On applying this synthesis to alkylidene com- 

 pounds of camphor, the authors obtained, instead of the expected 

 tertiary alcohols (II.), compounds of the formula (III.): — 



/CH R. /C ! CH • R., • Rj 



C 8 H 14 < I .OH C 8 H 14 < I OH /CH.CH( 



X c/ X C< / C 8 H/ I \R 2 



\r 2 \r, Xco 



I. II. * III. 



Hydrogen and the alkyl radical of the magnesium organic compound 

 had therefore become attached to the double linking. In connection 

 with this experiment, Boedtker 3 ) undertook the examination of the 

 behaviour of ethyl and of benzal menthone. He established that 

 neither ethyl menthone reacts with alkylmagnesium bromides; benzal 

 menthone also behaved like benzal camphor, inasmuch as substitution 

 products of the formula (IV.) were easily formed. In the pure state, 

 namely in the form of two crystallised isomerides, Boedtker only 

 obtained ethyl benzyl menthone, m. p. 102,5 to 103,5°, and 89 to 91°, 

 and the phenyl benzyl derivative (V.) (menthodiphenyl methane): — 



/ C 6 H 5 



.CH • CH( CH • CH(C 6 H 5 ) 2 



C B H / I \R C 8 H / I 



\co x co 



IV. v. 



*)- Atti R. Accad. dei Lincei Roma [5] 16, I. 665. Accord, to Chem. Zentralbl. 

 1907, II. 241. 



2 ) Compt. rend. 142 (1906), 677, 971. 



3 ) Ibidem 145 (1907), 329. 



