May 2s, 1914 
Aroma of Hops 
151 
IDENTITY OF AI,COHOIf AND ESTERS OF HOP OIE WITH MYRCENOL AND 
ITS ESTERS 
If present in the oil, oxygenated constituents should have a tendency 
to concentrate themselves in the fractions above the temperature of 
185° C. Therefore fractions 6, 7, and 8 were analyzed in order to deter¬ 
mine their elementary composition. Granting that the separation of 
constituents is at most only partially effected by fractionation, the 
determination of the carbon and hydrogen content of these fractions 
should show the presence or absence of oxygenated compounds. The 
oxygenated compounds of a saponified oil are usually alcohols of the 
formula C 10 H 18 O. The fractions in question gave the following results: 
Fraction 6 . —Carbon, 81.7 per cent; hydrogen, 11.1 per cent. 
Fraction 7.— Carbon, 80.0 per cent; hydrogen, 10.6 per cent. 
Fraction 8 . —Carbon, 81.4 per cent; hydrogen, 11.3 per cent. 
C^H^O requires 77.8 per cent of carbon and 11.7 per cent of hydrogen. 
The somewhat higher carbon content of the fractions may be explained 
by the fact that adhering traces of hydrocarbons were not completely 
separated in the earlier fractions. Oxygenated constituents of the 
nature of alcohols with the composition C 10 H 18 O are strongly indicated 
in the fractions mentioned. 
Since Barbier (1901) states that myrcene is capable of being hydrated 
chemically with the formation of an alcohol C 10 H 18 O, called “myrcenol,” 
it was thought that the alcohol of hop oil might be allied to this com¬ 
pound. Furthermore, it is possible that an alcohol like myrcenol could 
occur in company with the terpene myrcene, from which it is capable of 
being prepared. 
For a further comparison of the above fractions with myrcenol, Table 
X was prepared. 
When it is remembered that the fractions contain admixtures of other 
constituents incapable of being separated by fractionation, the prop¬ 
erties of the fractions compare very favorably with those of myrcenol. 
Sufficient similarity exists among the various properties, especially the 
boiling point, specific gravity, and refraction, to indicate the presence 
of an alcohol similar to myrcenol in the fractions recorded. 
In this connection it was deemed advisable to call attention to the 
esters of the oil of hops, which are present in considerable proportion, 
and to compare the chief ester fractions of the oil with the acetic ester 
of myrcenol. As the fractionation of the oil proceeded, it was observed 
that the esters concentrated themselves in the fractions boiling at 185° 
to 225 0 and 225 0 to 260° C. Although the fractions were by no means 
pure esters, a comparison of the physical properties with those of the 
known esters of myrcenol shows that the esters of the oil boil at much 
higher temperatures than free alcohol. This is readily explained when 
