433 
‘in -nerol.. Verley concludes, therefore, that lemongrass oil contains, in addition to 
citral “qa”. about 6 to 7 per cent. of neral. — 
ge Citral “bh” would then be the aldehyde neral corresponding to ai 
“A total synthesis. of linalool. —The methods for preparing artificial linalool. are all 
based on rearrangement reactions, no direct synthesis hitherto being known. Hence, 
inactive linalool was arrived at by starting from its isomeride geraniol, or from myrcene. 
A total synthesis has now been effected by L. Ruzicka and V. Fornasir*) who made use 
of ‘Nef’s2) reaction passing oif between sodioacetylene compounds and ketones. They 
started from methylheptenone (I) obtained by Verley ’s method by boiling citral with 
‘soda solution (vide the preceding abstract), which they dissolved in absolute ether; then 
a suspension of sodium amide was added and a slow current of acetylene iroduerd 
into the well-chilled mixture. There resulted in a yield of 80 p.c., dehydrolinalool (Il), 
. a cdlourless limpid oil, reminding of the smell of ict disentenone and citral; b.p. 91 
to 93° (12 mm.). The acetylene linking is evidently the reason why the pleasant smell — 
resinous precipitate on addition of ammoniacal silver nitrate. Its phenyl urethane melts 
at 88°. Reduction of dehydrolinalool to linalool (III) is effected by adding sodium to 
‘the ethereal solution of dehydrolinalool; when the evolution of hydrogen has ceased, 
water is added until the sodium is dissolved. The linalool resulting boiled at 86 to 88° 
(13 mm.) ; disc 0.8649 and 0.8654; BReny Bretnane, m. a 63 to 65°. 
. Se CH-CHs-CH.-COCH, - CHICH —> | 
¥ oot HsC Methylheptenone (I). ‘ Acetylene. ) ae 
CH; H.C . a CHs 
ce CH-CH,-CH,-C-CiCH + Hy —> © C:CH-CH,-CH,-C-CH:CH, 
HAC | OH HsC OORT 
; Dehydrolinalool (Il). , Linalool (III). 
Citronellol.— H. J. Prins*) undertook to separate citronellol into its isomerides by 
fractional distillation, but without success. He used in his experiments a citronellol 
obtained by reduction of citronellal which had been purified carefully by means of its 
b isulphite compound, as well as a citronellol resulting from its hydrate by steam- 
distillation in presence of sulphuric acid. 
Prins ascribes the following constants for purest citronellol, v.e., the mixture of the 
Ae ee freed from serait, &c.:— d Pourwo 0.867 to 0.869, Np20 1.4586 to 1.4589. 
? On p. 91 of our Report April 1915 we dealt ith a paper by 1 Meerwein*) on the 
reaction passing off in the transformation of borneol into camphene. This paper’ is 
n0w supplemented by a communication of the same author®), on cyclic rearrangements 
occurring on splitting off water Srom alacyche alcohols. - 
In the first paper, Meerwein was able to prove that the atomic are beTtiGh occurring 
transformation of borneol into camphene (Wagner’s rearrangement)®) is not limited 
(0 the bicyclic borneol and related compounds, but likewise passes off in the same 
anner_on abstracting water from monocyclic alcohols of similar structure. 
» 7) Helwet. chim. acta 2(1919), 182. — %) Liebig’s Annalen 308 (1899), 264. ) Compare also K. Hess and 
H. Munderloh, Berl. Berichte 51 (1918), 377. — *) Chem. Weekblad 15 (1918), 1378. — *) Liebig’s Annalen 405 
1 4), 129. — *) Ihidem 417 (1918), 255. — °) Compare p. 115 of this Report. 
of linalool does not manifest itself. In alcoholic solution the body gives a yellowish 
