Schorger—Chemistry of American Conifers. 751 
from the remainder, but even in this case the difference was less 
than anticipated. 
The distillation experiments lasted from May to November. 
The yield of oil was greatest during May and November but the 
total borneol content of the oils was greatest in August and 
September. 
The first fraction consisted of 1-a-pinene and contained a small 
amount of furfural. Eegardless of the rotation of the original 
oil the pinene fractions were decidedly 1-rotatory. For example, 
an oil having the rotation a D20 o + 38.68° gave a fraction having 
the boiling point of pinene and the rotation a D24 o -19.88° 
Pinene nitrolpiperidine melting at 117-118° was prepared from 
it. /?-pinene and camphene were not found. 
The oil distilling between 170-180° contained dipentene, limo- 
nene and sylvestrene. The first two terpenes were shown to be 
present by obtaining two tetrabromides by fractional crystalli¬ 
zation melting at about 113° and 123.5°. Sylvestrene was identi¬ 
fied by preparation of the dihydrochloride melting at 72-72.5° 
and by the deep blue color which the sylvestrene, regenerated 
from the dihydrochloride, gave with acetic anhydride and con¬ 
centrated sulphuric acid. Sylvestrene is one of the rarer ter¬ 
penes and this appears to be the first record of its occurrence in 
any American oil. 
Borneol was identified by oxidation to camphor melting at 
173-174°. The combined acids consisted of acetic and caproic 
acids. After removal of the esters a sesquiterpene was obtained 
in the fraction b. p. 250-280° and a deep green oil between 280 
and 310°. The sesquiterpene had the following properties: b. p. 
260-280° ; d 20 ° 0.9292; n D2 . 6 ° 1.4994; a D26 ° +6.4°. The hydro¬ 
chloride prepared from this fraction crystallized from ethyl ace¬ 
tate in thin plates and melted at 132-133°. This sesquiterpene, 
“libocedrene”, could not be identified with any of the sesqui¬ 
terpenes recorded in the literature. Lack of material prevented 
a more detailed study. 
The composition of the oil is the following: furfural, trace; 
1-a-pinene 12—16%; d-sylvestrene, d-limonene and dipentene 
54-58%; bomyl acetate 8% ; free borneol 4% ; libocedrene 6- 
7% ; “green oil” 2%. 
