— 123 — 



to the character of the ketone, in view of the high specific gravity 

 it does not appear to be a question of the as yet unknown mentho- 

 carvone, but probably of a representative of the bicyclic system. 



Citronellol. The reduction of unsaturated primary fatty alcohols 

 by ammonium metals 1 ) was also applied by E. Chablay 2 ) to citronellol, 

 from which a pleasantly smelling hydrocarbon was obtained which 

 had the following constants: b. p. 168 to 169 (ordinary pressure): 

 d 15 o 0,789; d 2 2,5Q 0,777; n D22,6° 1,4484. Elementary analysis showed 

 85,47 and 85,62% C, 13,37 and 13,40% H i calculated for C 10 H 20 

 (dimethyl-2-6-octene-2) 85,72% C and 14,28% H. The author at- 

 tributes the slight differences to imperfect purity, but does not doubt 

 that the body obtained actually represents dimethyl- 2 -6-octene-2, 

 and possesses the following formula corresponding to the citronellol 

 formula : — 



CH 3 — C(CH 3 ) = CH — CH 2 — CH 2 -CH(CH 3 )-CH 2 -CH 3 



Nerol. We have already 3 ) briefly referred to the properties of 

 the pure nerol produced by v. Sod en and Treff. The method 

 of production recently followed by the above-mentioned authors 4 ), is 

 as follows : a mixture of diphenyl urethanes produced from nerol con- 

 taining geraniol, can readily be split up by fractional crystallisation in 

 suitable solvents (petroleum ether, methyl alcohol), owing to the differ- 

 ences in solubility. The alcohols are then regenerated from the pure 

 urethanes by saponification, and purified in the usual manner. The 

 crude material was crude nerol produced from petitgrain oil, which 

 no longer reacted with calcium chloride. Nerol, which as is well known 

 absorbs 4 atoms bromine, yields with bromine a finely crystallising 

 tetrabromide of the m. p. 118 to 119 . The results of the oxidation 

 of nerol do not allow definite conclusions to be drawn with regard 

 to its constitution. The authors assume that with careful oxidation 

 citral a, the aldehyde which chiefly occurs when oxidising geraniol, is 

 only formed in small quantities, and that with chromic acid there is 

 formed either principally citral b, or a new aldehyde which, however, 

 hardly differs at all in the odour from the two former; with regard 

 to the occurrence of the two citrals, this would point to atomic transposition. 

 It should still be mentioned that v. Soden and Treff have also suc- 

 ceeded in producing a solid geraniol tetrabromide, by allowing 4 parts 

 by atomic weight of bromine to act on geraniol dissolved in cold 

 chloroform. The oily bromide was left standing for several weeks in 



x ) Compt. rend. 140 (1905), i343> J 396. 



2 ) Ibidem 143 (1906), 123. 



3 ) Repor April 1904, 109. 



4 ) Berl. Bterichte 39 (1906), 906. 



