7 CPR Le. eee a ee ee J 
2 abn Nae Pak ae Ce 
F Are 
142° REPORT OF SCHIMMEL & Co. APRIL 1914. a 
ay 
7 ‘ 
In addition to the above alkyl-derivatives Haller has prepared a few others. We need ~ 
say very little about the method of preparation. It is based upon the action of sodium 
amide upon the ethereal solution of the ketone and upon treatment of the product of — 
reaction with alkyl halogenide, exactly as in the preparation of the alkyl menthones’). 
Dimethylthujone. . B.p. 92 to 94° (12mm.); dj¢ 0,916; [«¢]—19°45’ — 
Diallylthujone . . ,, 147,5 ,, 148,5°(18mm.); d2> 0,9352; —- Np»o 1,4850 
Triallylthujone . . 4 173 ,, 175° (21 mm); d= 0,9467; — Mp0 1,5016 
Dimethylisothujone. ,, 120 ,, 122° (19 mm.) —- _ — | 
Allylisothujone . . ,, 144 ,, 146° (18mm.); d2> 0,9280; — Np»0 1,4930. 
Pulegone. M. Saizeff?) has prepared ethyl-3-pulegol from pulegone and ethyl- 
magnesium bromide. The body boils between 112 and 115° (16 mm.); ds 0,9223 ; 
[<]p + 43,22°. Oxidation with 1p.c. potassium permanganate solution in the presence 
of magnesium sulphate in the cold, gave rise to formic acid, methyladipic acid (@), 
and possibly a body Cie Hos Os. 
Carvone and eucarvone. In his 116th monograph on terpenes and essential 
oils, O. Wallach*) describes the reduction of carvoxime and eucarvoxime with palladium 
hydrogen. When carvoxime is reduced with hydrogen in the presence of colloidal 
palladium and the supply of hydrogen is restricted to such an extent that only 
1 molecule of hydrogen is supplied for every molecule of oxime, the result is not 
dihydrocarvoxime but a beautifully crystallising oxime, which, after repeated recrystal- 
lisation, melts between 66 and 67°, and when resolved with acids, affords carvotan- 
acetone, which latter substance yields the normal carvotanacetoxime, m.p. 75°. At 
first the oxime with the low m.p. was regarded as a stereoisomeric modification of | 
ordinary carvotanacetoxime. Closer investigation, however, showed that the oxime 
with m. p. 66 to 67° represented mixed crystals from active carvoxime (m. p. 72°) and 
active carvotanacetoxime (m.p. 75°), which are remarkably stable and do not even 
undergo a perceptible change in habit when repeatedly recrystallised. If, in the process 
of reducing carvoxime, the supply of hydrogen is not restricted, ammonia, carvacryl- 
amine, and tetrahydrocarvone result, but no tetrahydrocarvoxime. This fact is worthy 
of note, because carvone is capable of being reduced to tetrahydrocarvone, and it 
follows therefore that the ethylene linkage does not readily dissolve when it occupies 
a position adjacent to an oxime-group. On the other hand, the vicinal position of the 
ethvlene linkage appears to facilitate the attack upon the oxime-group of palladium 
hydrogen, and this is especially evident when carvoxime and carvotanacetoxime are 
severally treated with palladium hydrogen under precisely similar conditions. It would 
appear that the double-linking which exists in carvone conjugated with carbonyl is 
less easily reduced than the double-linking in the extra-cyclical position which is 
present at the same time, whereas the reverse is the case when the linkages in 
question are present in an isolated position, as in carvotanacetone and in dihydro- 
carvone. Thus, according to Vavon*), free carvone, when reduced with platinum black 
and hydrogen, yields first of all carvotanacetone, and only yields tetrahydrocarvone 
when the reduction has progressed further. Our present formulz of molecular structure 
afford no explanation of these phenomena. 
1) Compt. rend. 156 (1913), 1199; Report October 1918, 146. — %) Journ. russ. phys. chem. Ges. 45 (1913), 
1571; Chem. Zentralbl. 1914, 1. 783. — *) Liebigs Annalen 408 (1914), 73. — *) Compt. rend. 158 (1911), 68; 
Report October 1911, 150. 
