985 
Now what about the relation of the glutaeonie acid in regard to 
this theory > 
I. Glutaconie acid may be obtained by a number of very different 
processes, which will be discussed here, briefly. 
A. Method of Conrap and Guruzerr '). By condensation of 2 mols. 
of malonie ester and 1 mol. of chloroform with sodium ethoxide, 
Na-dicarboxylglutaconic ester is formed which is then separated and 
saponitied, 
With this method of preparation are closely connected : 
1. that from tsoaconitic ester *) which is formed for instance, by 
incomplete saponification of the dicarboxylglutaconic ester. 
2. that from 6. ethoxy. a@ pyrone 3.5 dicarboxylic ester *) (formed 
by distillation of the diearboxyl ester ete). 
The melting points of the acids thus obtained mostly vary between 
130° —134°. 
B. PrcHmaNN-Broise *) based on the saponification of the glutaconic 
ester formed by cleavage of acetic acid from the acety/-3-ovyglutaric acid. 
C. Method of Morernstern and Zerner*). By saponification with 
strong alkali of the p-oxyglutaric dinitrile obtained by the action of 
potassium cyanide or dichlorohydrin a little glutaconic acid was also 
formed. The melting point is given here as 129—129°.5. 
D. Method of von PeGMANN®), which is based on the decomposition 
of cumalic acid (a-pyrone 3 carboxylic acid) by boiling with baryta. 
The acid so obtained is stated to melt at 1382—-134°. 
E. Method of Bucuxer’). The acid is formed by the saponification 
of the dimethyl ester formed in company with that of Trans 1. 2. 
trimethylene dicarboxylic acid by cleavage of nitrogen from the 
acryldiazoacetic ester (pyrazoline 3.5. dicarboxylic ester.) 
The acid so obtained melted at 127—128°. 
In addition there occur in the literature a few other methods of 
preparation or formation, of less importance. 
In Ricurer’s Lexicon a distinction is made between: 
cis-propen. ay. dicearbonsäure (cis-Glutakonsäure) 
and isom-propen. ay. dicarbonsäure (Glutakonsäare). 
The statements in the literature relating to the above syntheses 
1) Ann. 222. 253 (1883); Ber. 15. 2841 (1882) etc. 
2) ConrAD and GuTHZEIT: loc. cit. 
3) GuTHzEIT and DresseL: Ber. 22. 1425 (1889). 
4) Ann. 261. 157 (1891): Ber. 24. 3256 (1891), Bull. (3) 29. 1013 (1903). 
5) Sitz. ber. Akad. Wien 119. 589 (1910). 
6) Ann. 264. 301 (1891). 
7) Ber. 23. 703 (1890), Ann. 273. 238 (1893). 
