Chemistry of Essential Oils

1.

C 9 H 14 O

6-980

150° to 155°

2

CnH 18 O

1-020

174° to 176°

78 THE CHEMISTEY OF ESSENTIAL OILS

-each successive investigator differing somewhat in his results from

previous workers. Furfural, diacetyl, and methyl alcohol are present

in the distillation waters of the oil.

Fritzsche & Co. claimed : to have isolated a mixture of ketones which

they termed vetiverone, having the empirical formula C 13 H 22 O and a

specific gravity about 0*990. Two alcohols were also found having the

following characters :—

Formula C9H14

Specific gravity 6-98

Boiling-point at 10 mm150° t

, Genvresse and Langlois^2 have isolated a sesquiterpene from the oil,

C 15 H 24 , which they term vetivene. It boils at 262° to 263° at 740 mm.,

and has a specific gravity 0*932 and optical rotation + 18° 19'. A ses-

quiterpene alcohol, C 15 H 26 O, was also isolated, which the discoverers

term vetivenol. It boils at 169° to 170° at 15 mm., and has a specific

gravity I'Oll at 20° and optical rotation + 53° 43'.

An acid, or mixture of acids of the empirical formula C 16 H 24 O 4 was

also found, and the authors consider that the characteristic odour of the

oil is principally due to the presence of esters of these acids with

vetivenol.

Bacon^3 considers the acid or acids present in this oil to correspond

with the formula C 15 H 24 O 2. He also found benzoic acid present in the

oil. The most recent work on this oil is that of Semmler, Risse, and

Schroter.^4 According to these chemists the formulae given by Genvresse

and Langlois are incorrect, the correct ones being, for vetivenol C 15 H 240

and for the acid C 15 H 22 O 2. The last-named investigators examined an

oil possessing the following properties : d 20 °- 1*0239; AD + 31°; n^,^

1*52552. They distilled 400 grms. of this oil, at 12 mm., intD the fol-

lowing four fractions :—

(A)

(B)

(C)

(D)

Boiling-point

l> >>

»> tt

129 °

170°

190°

250°

to 175°,

„ 190°,

,, 250°,

„ 300°,

23 per

34

S

30

3311.

Fraction (D), when subjected to further distillation, was s^lit up into
two portions, as follows :—
(D, a] BDiling-point 138° to 260° (13 mm.), 28 per cent.
(D, b) „ „ 260° „ 298° (13 mm.), 62
Analysis showed that the portion (D, b) consisted of an ester C 30 H 4402
of the acid C 15 H 22 O 2 and the alcohol C 15 H.)4O. The characters of the
free alcohol are as follows : boiling-point 170° to 174° (13 mm.) ;
d. 2 0o 1-0209; aD + 34° 30'; nD 1-52437; molecular refraction 65*94.
Hence the vetivenol of this fraction can only be a tricyclic, simply un-
saturated alcohol. The acid C 15 H 22 O 2 boils at 202° to 205° (13 mm.), is
tricyclic and is called vetivenic acid by the authors. Its methyl ester
boils at 170° to 173° (18 mm.) and has the following characters : d00o
1-0372 ; aD + 42° 12'; WD T50573 ; molecular refraction 71-05.
Fractions (A) and (B), when subjected to repeated fractional distilla-
tion in vacuo yielded a fraction boiling between 173° and 180° (13 mm.),
from which vetivenol was obtainable by treatment with phthalic anhy-

1

DM.P., 142415 (1902) •

J

Comptes rcndus, 135 (1902), 1059.

'•' Philipp. Jour. Sc., 4 (1909), 118.

4

Bericht, 45 (1912), 2347.