— 113 — 
these completely in many notable reactions. For instance, sodium 
bisulphite attaches itself to the a -jS- double -linking with formation of 
a hydrosulphonate. Hydroxylamine and semicarbazide show the same 
behaviour under certain conditions. The reduction and oxidation 
allow an insight into the nature of the reaction -products. The ex- 
periments made by Fit tig and Baeyer have shown that the double- 
linkings of unsaturated acids endeavour to change from the ^-y- into 
a-/S-position. The same tendency seems also to exist in unsaturated 
ketones, as is shown by the conversion of dihydrocarvone into car- 
venone, of pulegone into isopulegone. Zinc dust and glacial acetic 
acid, or soda liquor, reduce only the a-yS-double-linking; sodium and 
alcohol also the ke to -group, — whilst a double-linking not situated 
in the a-^-position as a rule cannot be reduced. Dilute solution of 
permanganate oxidises unsaturated ketones into keto-glycols, from which 
di-ketones are formed by loss of water. Many unsaturated ketones 
also change already by the oxygen of the air, i. e., they are auto- 
oxidised. When carvone, for example, was shaken with alcoholic 
baryta liquor and air, the formation of zl^-menthenedione (2,6) was 
observed, whose dioxime was also obtained from carvone oxamine- 
oxime by oxidation. The separation of two unsaturated ketones was 
accomplished in two cases. In the one case it was a question of 
mixture of a-/3- and ^-^/-unsaturated ketones (pulegone and isopule- 
gone). Here, the property of the a-/5-unsaturated ketone of becoming 
polymerised on reduction with aluminium amalgam, was used to effect 
the separation. In the second case, where the object was the 
separation of two a-/?- unsaturated ketones (carvone and zl^-men- 
thenone-[2]), it succeeded by conversion of the carvone into car- 
vacrol over the hydrobromide compound, and removal of the same 
by means of dilute soda liquor. A discussion of the nature of the 
double-linldng in connection with the above experiments concludes 
the theoretical part of the treatise. 
M. Konowalow^) has continued his work on the nitrification 
of terpene ketones, and included in it fenchone, pulegone, dihydro- 
carvone, and carvenone. Fenchone when heated with nitric acid to 
120° to 130°, forms a nitro-product C^^^ (NOg) O of the melting 
point 86^ to 87°, which is soluble in alkali, and which can be reduced 
with zinc and glacial acetic acid into an amine, and a nitrofenchone 
insoluble in alkali, of the melting point 96,5° to 97,5°, wich on re- 
duction yields oxyfenchone. When pulegone was nitrified, products 
soluble and insoluble in alkali were obtained, — of the latter, compounds 
^) Journ. Russ. phys. chem. Soc. 35 (1903), 903. According to Chem. Central- 
blatt 1904, 1. 282. 
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