Pam ot s 
: NOTES ON SCIENTIFIC RESEARCH. 131 
m. p. 247 to 248° forms a p-nitrobenzoate, m.p. 44 to 45°, the one with m. p. 235 to 
236° yields a p-nitrobenzoate with m.p. 82 to 83. 
The observation that when bornylene is oxidised camphenanic and isocamphenanic 
acids are formed is of importance. These acids having been obtained both by 
Henderson and Sutherland and by Aschan*) as decomposition-products of camphene, 
it follows that camphene and bornylene are more closely related than had hitherto 
been assumed. 
C. Harries and R. Haarmann?) report on bornylene ozonide. They treated bornylene 
which had been purified by Tchugaeff’s method®), in a hexane solution with washed 
(8 p.c.) ozone, and obtained a white ozonide in the form of a precipitate. This ozonide 
was volatile and non-explosive, and decomposed very slightly when boiled with water. 
In order to carry out the resolution of the ozonide, the authors ozonised bornylene in 
glacial acetic acid instead of in hexane, and then heated the solution on a water-bath. 
By this method they obtained as principal product a pale yellow oil, b. p. 105 to 125° 
(18 mm.) and a solid substance, b. p. 125 to 150° (18 mm.). The liquid fraction con- 
tained a dialdehyd, whereas the solid portion probably contained an aldehydo-acid. 
a-Pinene. On pp. 131 and 134 of our last October Report we referred to the 
interesting investigations by E. Buchner and W. Weigand on the action of diazoacetic 
ester upon bornylene and camphene. More recently, Buchner, in conjunction with 
K. Rehorst*), has also treated «-pinene (I) with diazoacetic ester and has obtained 
such products as were to be expected from the presence in the pinene-molecule of 
an endocyclic double bond®). The authors used an inactive «-pinene, regenerated from 
the nitrosochloride by boiling with aniline and as a reaction-product they obtained 
1,6, 6-trimethylcyclo-(0, 1, 4°’, 1)-octane-2-carboxylate ®), Ci: Hiz-CO2 C2 Hs (II). The free acid 
melts at 105°. Resolution of the acid with aqueous potassium permanganate solution 
in the presence of sulphuric acid afforded methylcyclopropane-1, 2, 3-tricarboxylic acid (III), 
- m.p. 192. The m. p. of the trimethylester of this acid (76,5°) suffers no depression 
after the admixture of synthetic ester’). In the course of this reaction they obtained 
as by-products terebinic acid and an acid Ci.Hi6QOx, the latter arising apparently from 
the condensation-product by the oxidation of the methyl-group in the 1-position towards 
a carboxyl-group. In the course of treating non-regenerated, optically active pinene 
with diazoacetic ester, an acid Ci2HisO2 had been formed as a by-product; this acid 
is presumably derived from the semicyclic #-pinene and represents a spirane-derivative. 
CH CH C-CH 
eee oc ct, nce Pe HO2C-C-CHs 
| | Noch Neo 
| any C(CHs)» Be CO.C.H; Wr CO2H 
ne. CH HG, : 
ited EH HO.C-CH 
CH, CH, 
(I) a@-Pinene. (Il) Trimethyltricyclooctane-2-carboxylate. (III) Methylcyclopropane- 
1,2, 3-tricarboxylic acid. 
1) Comp. Report October 1911, 134; April 1912, 169. — %) Berl. Berichte 46 (1913), 2595. — 8) Comp. 
Report October 1912, 146, 147. — +4) Berl. Berichte 46 (1913), 2680. — 5) Before this A. Loose [Journ. f. 
prakt. Chem. \\. 79 (1909), 505] had already reacted upon pinene with diazoacetic ester, but had been unable 
to isolate any cristalline products. — %) This compound is named according to A. von Beyer’s method. 
Comp. our last Report, p. 135. — 7%) Comp. Buchner and H. Dessauer, Berl. Berichte 27 (1894), 878. 
Q* 
