989 
benzene at 136°—138°. In contrast with the acids mentioned under 
a and c it instantly reduced alkaline permanganate. 
c. Cis-trimethylene 1.2 dicarboxylic acid has not been found by 
Bucuner in this synthesis. This ether is the first to pass into ether 
as it is very insoluble in water. The m.p. was 139° in agreement 
with the statements in the literature; on mixing with acid 4 or 
otherwise prepared glutaconic acid a considerable melting point 
depression occurred. The acid did not reduce alkaline permanganate 
and was not attacked by sodium amalgam at boiling heat. 
0.1131 gram required: 8.35 cc. N/9.48 baryta M = 130.2 
Theory M = 130.05 
I hope to refer to a few properties of these trimethylenedi 
carboxylic acids later. 
Identity of the glutaconic acids obtained. 
The glutanic acid obtained according to the methods A—E had 
always fairly well the same melting point (186°—138°); moreover, 
on mixing the various specimens the melting point remained quite 
unchanged. The appearance of the erystal-mass and the relative 
solubilities are the same for all specimens investigated. It is, there- 
fore, certain that all the methods investigated yield the same acid. 
The identity of these acids is confirmed by the results to be 
discussed in the communication to follow; all kinds of the acid 
bebaved in the reactions to be stated, in exactly the same manner. 
In each method of preparation it is was tried carefully whether even- 
tually an isomeric glutaconic acid was present, but always without 
any result, however. 
The Bicuner diazoacetic ester synthesis has also a double theore- 
tical importance. 
1st. Let us imagine the linking as follows: 
\ 
C#,= CH — COO Ae EH, — CH- C OOM 
N | ee 
oc. c3e— |I EN OOC — C1 = hi = 
If now nitrogen is split off we obtain the glutaconic acid in the 
symmetric form as first proposed by PerKIN and TATTERSALL *) 
HOOC—CH—CH—CH—COOH. 
| | 
2nd, The formation of cyclopropane derivatives beside an isomeric 
1) Soc. 87, 361 (1905). 
