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TT .: 
NOTES ON SCIENTIFIC RESEARCH. 133 
thorium oxide and heated to 400°, by which method they obtained 124 grams of crude 
ethyl-n-amylketone. Reduction of the ketone in a solution of moist ether and sodium 
afforded 106 grams of crude ethyl-n-amylcarbinol, from which body in turn they 
obtained 197 grams of the acid phthalate. By fractional crystallisation from methyl 
alcohol the authors succeeded in preparing the optically pure strychnine salt of the 
d-phthalate. When regenerated from the phthalate, d-ethyl-n-amylcarbinol had b. p. 76° 
(16mm.). The properties of ethyl amylcarbinol and its derivatives, as observed by 
Pickard and Kenyon and by ourselves are as follow: — 
: M.p. of th B.p. of the M.P. of the 
d-ethyl-n-amylcarbinol : ‘ y : 
acid corresp. semicarb- 
Bap: ap Np20 phthalate ketone azone 
76° (16mm.) dee 66 to 165 to 
Pickard and Kenyon ; 168 to 172° 0, 8247 + 6,79° { 4252 08° 166° 112° 
(753 mm.) *) 
: 178,5 to diso +06,43° 1,4275 65,5 to 170° ee 
Schimmel §Co...{/ 178: 15 pe 
ee 4790. 0.8276 66° 
Chromic esters of terpenic alcohols. H.Wienhaus’) has discovered that by 
merely shaking up dilute aqueous solutions of chromic acid with certain alcohols, 
chromic esters may be formed. When the alcohol has been dissolved in light petroleum, 
the layer of the latter at once acquires a red colour, and it is only necessary to 
evaporate the solvent in order to obtain the organic chromate. A better method is to 
treat the alcohols in a solution of carbon tetrachloride or light petroleum with an 
excess of dry chromic anhydride, and to pour them off from the unattacked reagent, 
which has become partly deliquesced as a result of the water which has been generated. 
It is best to evaporate the solutions in a vacuum-desiccator. Chromic acid being the 
agent for oxidising primary and secondary alcohols, the possibility of an ester of 
chromic acid being formed is restricted to tertiary alcohols. It is necessary, besides, 
that the remaining molecule shall be stable towards oxidising action. 
x Chromic esters are most difficult to saponify with alkaline liquors and baryta 
solution, probably because of their insolubility in water. When heated with alcoholic 
liquors, the alcohol is readily regenerated. 
In organic chromates, chromic acid can no longer be identified by the usual test 
with hydrogen peroxide in ether. 
The formation of a chromate may often serve to establish the tertiary character of 
an alcohol. If the solution of the alcohol in light petroleum, when treated with chromic 
acid, remains red for a long time, there is no longer any doubt of the tertiary 
character of the alcohol. If the colours of the solution should soon become mixed 
this fact would not prove anything, because not only primary and secondary, but 
under certain conditions tertiary alcohols also oxidise more quickly. 
Methylfenchol, the product of reaction of fenchone and magnesium methyl iodide, 
gives a beautifully crystallising chromate. Contrary to methylfenchol, which is slightly 
dextrorotatory, the chromate is levorotatory ([@]Lireq — 30,0°). It melts at 130°. The 
chromate of ethylfenchol is less readily soluble than that of methylfenchol. It does 
not melt, but turns black at 140°; [e]Lireq + 22,59. The chromate of methylborneol 
constitutes small needles of a bright orange colour, decolorising at 105° but without 
melting. The chromate of cedrol forms clear, yellowish-red, narrow prisms, melting 
into a black liquid at 115°; [@]Lireq + 79,4°. Ledum camphor, or ledol, as Wienhaus 
1) Crude product. — 7) Berl. Berichte 47 (1914), 322. 
