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Seas Notes ON SCIENTIFIC RESEARCH. 153 
F “The Shraride: from edikvdiosuéatvone (Il), on bromination in glacial acetic acid 
ica wit; heating, is converted into a tribromide (V), m.-p. 104 to 105°, which on 
shaking with a 2 percent. potash solution yields an acid, m.p. about 170°. Strangely, 
the isomeric dibromide (III) from tetrahydroeucarvone adds no more bromine when 
_ treated under the same conditions. ) 
= Furthermore, Wallach reports on the interaction of the iibraride CyoHigBr2O itt ? 
q m. p. 68°, from tetrahydroeucarvone with caustic potash. Treatment with aqueous 
_ potash of this dibromide resulted in a saturated monobasic acid, m. p. 91.5 to 92.5°') 
and in volatile products which Wallach now investigated closely. They form a mixture 
boiling principally between 35 and 75° and 93 to 95°, at 8mm.- The lower- -boiling 
fractions boiled, under ordinary pressure, in the main at 138 to 140° and contained 
probably hydrocarbons® owing to a secondary reaction. The higher fraction boiled, 
under ordinary pressure, irregularly up to 230°, ‘showed bright yellow coloration and 
high density 9 988° at 20°). No characteristic products were obtainable from this 
_(I) 8-Dihydroeuearvone. ) Pibromide of m.p. 71 to 72° from 
HS -dihydroeucarvone, 
\} 
sis pe ; Bae -{- H.O. CHs 
| 
C—Br ee Bags CBr 
Hc/ \c=0 HCH \\cHCO.H , ‘BHC co. 
des ~ CHBr Cv Cs tC ay 
PEER SP x : i CH 
FBC! = LZ i 4 ur CHs H.C! ws 3 
: : CH, ; CH; ; CC CH, 
(Ill) Bromide of m. p. 68° from v) Probable formula of tribromide 
tetrahydroeucarvone. — CioH\;Br30 from @-dihydroeucarvone. 
' (EV) a-Cyclogeranic acid. 
preparation. On reduction with palladium and hydrogen, the fraction added readily 
hydrogen and yielded a colourless liquid boiling principally between 223 and 225° 
(dsoo 0.9690). It formed a semicarbazone, m.p. 212 to 213°, and an.oxime, m. p. 55 to 
56°. On oxidation with potassium permanganate two acids were formed, a volatile 
one smelling of isobutyric acid, and a non-volatile one which did not solidify. Possibly, 
it is here the question of a cyclic ketone with the carbonyl group in the lateral chain. 
_In any case, the compound is not identical with monohydroxytetrahydroeucarvone?). 
The volatile acid CyH:gO. mentioned above, m.p. 91.5 to 92.5°, is isomeric with 
_@-cyclogeranic acid. It is rather stable towards potassium permanganate, but never- 
_ theless can be oxidised in alkaline solution resulting in a mixture from which three 
acids could he isolated: — an acid CyoHy6O3 (m. p. 159 to 160°), an acid CyoHisO; 
_(m. p. 187°), and an acid, m.p. 90 to 91°. 
Wallach then deals with the interaction of dibromotetrahydroeucarvone with sodium 
; methoxide, which we referred to in our eae of 1918, 137. The result is a neutral 
ST PENT RII eee Te PEE AM Seng 9 al RI OME EE TI CO Ee Or ay 
1) Wallach, Liebig’s Annalen 414 (1918), 373; Report 19S, ISP ess : 
