NOTES ON SCIENTIFIC RESEARCH. 143 
»* In the reduction of eucarvoxime, as in that of carvoxime, the ultimate products 
which are. obtained depend upon the experimental conditions. As a general rule, 
reduction proceeds more rapidly and is more thorough when concentrated methyl- 
alcoholic solutions are used, than with dilute solutions. Thus, for instance, the prin- 
cipal reduction-product of 5 grams eucarvoxime in 50 to 60 cc. methylalcohol in the 
presence of 0,05 to 0,1 grams colloidal palladium and 10 cc. water, is a previously 
unknown crystalline modification of tetrahydroeucarvoxime melting between 56 and 57°. 
The tetrahydroeucarvone regenerated from the oxime has normal properties’). So far 
it has not been possible to reconstitute the new oxime when the regenerated tetra- 
hydroeucarvone is oximated. In contradistinction to the experience of von Baeyer, it 
was found that tetrahydroeucarvone affords without difficulty a readily-crystallising 
nitroso-compound, m. p. 104 to 105°. Tetrahydroeucarveol is obtained both by reducing 
tetrahydroeucarvone with sodium in alcoholic solution, and by reducing dihydroeucarveol 
with palladium and hydrogen. This tetrahydroeucarveol yields a phenylurethane with 
m.p. 74 to 75°. With the object of achieving partial reduction only, 15 grams of eucarvo- 
xime were shaken in a hydrogen-atmosphere with 0,02 grams of colloidal palladium and 
210 cc. of methylalcohol. The result was a new dihydroeucarvoxime, m. p. 122 to 123°, 
to which Wallach has given the 
name of 6-dihydroeucarvoxime, to CHs 
distinguish it from the previously- C 
aa. 
nown dihydroeucarvoxime. -Di- HC 
hydroeucarvone boils between 213 | | | | 
and 214°, a-dihydroeucarvone at H.C CH, uy de H.C CH, 
205°. These two bodies differ also | | | | 
in their density, refraction, and H.C C(CHs)> H,.C—— C(CHs)e 
the m.p. of their semicarbazones. 
Oxidation of ?-dihydroeucarvone (I) 
with chromic acid leads to §,2-dimethyladipic acid (Il). Distillation of the calcium-salt 
of this acid with soda lime in a hydrogen current afforded ,-dimethyl cyclopentanone 
(m. p. of the dibenzylidene compound 139°). From the above it follows that the structure 
of 6-dihydroeucarvone is as shown in (I). 
In conclusion, Wallach communicates certain observations made by him on the 
dicarvelones and dieucarvelones, bodies which are formed when carvone or eucarvone 
is reduced with zinc and soda liquor. These bodies are diketones, and occur in 
several isomeric modifications. Wallach has now succeeded in clearing up, at any 
rate in certain directions, the uncertainties which have hitherto prevailed concerning 
the constitution and the mutual relationships of these compounds. 
(1) 6-Dihydroeucarvone. (II) @,@-Dimethyladipic acid. 
On the action of heat upon ketoximes, see p. 148. 
Phenols and Phenol-ethers. 
Phenol-ether, Reduction. In our last April Report (p. 133) we referred to the 
experiments in reduction under high pressure and in the presence of a catalyser 
carried on by W. Ipatieff. In his most recent publication, this investigator®) describes 
the reduction of the phenols with an unsaturated side-chain. By using reduced nickel 
as a catalyst under high pressure, saturation of the double bond takes place first, 
and only after this has been accomplished is the aromatic nucleus reduced. 
1) Comp. Report April 1911, 165. — 2) Berl. Berichte 46 (1913), 3589. 
