Chemistry of Essential Oils

MYKTACEJE 341

Eudesmol, which has been also named eucalyptus camphor, was

first isolated from the oil of Eucalyptus piperital by H. G. Smith, who

found it to be a crystalline body melting at 79° to 80°, and having the

formula C 10 H 16 O, and being, in all probability, an oxide. Semmler and

Mayer,^2 however, consider it to be a bicyclic sesquiterpene alcohol, and

this has since been confirmed by Semmler and Tobias,

8

who give the

following as its characters:—

Melting-point

Boiling-point

Specific gravity.

„ rotation,

Refractive index ,

Formula

+ 31

78°

156° at 10 mm.

0-9884 at 20°

21' in chloroform solution

1-5160 at 20°

88-5°

283° at 755 mm.

• 35° 29' in chloroform solution

The same chemists have also made an examination of the sesqui-
terpene alcohol isolated from oil of Eucalyptus globulus by Schimmel
& Co.,^4 which they have named globulol. This body has the following
characters:—

Melting-point ....

Boiling-point ....

Specific rotation

Formula

Smith
5
has also isolated a new aldehyde from certain eucalyptus
oils which he has named aromadendral. It has been suggested by
Schimmel & Co. that this was identical with cuminic aldehyde, which
had previously been found in eucalyptus oil by themselves. An ex-
amination of Smith's work on the subject, however, leaves no room for
such an assumption, and it is clear that aromadendral is not identical
with cuminic aldehyde.
Baker and Smith have recorded the following details (see pages
342-44), of 118 species of eucalyptus oils, arranged in groups according
to their dominating constituent.
Aromadendral was extracted fron the higher-boiling portion of the
oil of Eucalyptus rostrata by the aid of sodium bisulphite in the usual
manner. When purified it had an odour reminiscent of cumin aldehyde,
was almost colourless, being slightly yellow in appearance, and was
highly laevo-rotatory. The specific gravity at 20° C. = 09534; specific
rotation [a]D - 7394°; refractive index at 20° = 1*5066; the oxime
melted at 84° to 85°, and the phenylhydrazone at 105° to 106° C. By
arranging these results in tabulated form with those of cuminaldehyde
the differences appear distinctly marked:—

d 15 J 0

Optical Rotation

Melting-point Oxime

,, Phenylhydrazone.

Refractive Index at 20°

Cuminaldehyde.

0-9818

Nil

58° to 59°

126° „ 127°

Aromadendral.

0-9569

[a]D - 73-94°

84° to 85°

105° „ 106°

1-5066

1

3 Jour. ofProc. Roy. Soc., N.S.W., 33 (1899), 86. *Berichte, 45 (1912), 139Q.

Ibid., 46 (1913), ^026. 6 4 Report, April, 1904, 51.

Jour. ofProc. Roy. Soc., N.S.W., 34 (1900), 1.