ACETO ACETIC ESTER 21 



It is a colorless oil boiling at 271 "-272°, it has a specific gravity of 

 1.0505 at 14.1.° Treating this with alcoholic potash and then sulfuric 

 acid, glutaric acid, CH2 CO2 H 

 CH2 



CH2 CO2 H, is produced. Methyl-aceto-glutaric 

 ester, formed similarly from sodmethylacetoacetic ester boils at 280°- 

 281° and has a specific gravity of 1.043 ^t 20.° When this is saponified 

 potassittni methyl-glutarate CH (CH3) CO2 K 



CH2 



CH2 CO2 K is produced which is a crystal- 

 line substance melting at 76.° The zinc and silver salts were described- 



KRESSNER, Q., 1878. 



Ann. Chem. 192, 135-141 ; J. Chem. Soc, 24, 783; Ber. 11, 1245; Jsb. 



Chem. 1878, 721. 



Synthesis of Pyrotartaric Acid from a=Methyl=aceto=succinic 



Ester. 



«-Methyl-aceto-succinic ester saponified yields pyrotartaric acid 

 identical with that produced by Conrad, (Ann. Chem. 188, 226,) from 

 /9-methyl-aceto-succinic ester. The two equations are ( i ) a 

 CH3 

 CO 



C (CH3) CH2 



CO2 C2 H5, CO2 C2 H34-3 K0H = CH3 CO2 K + 



CH (CH3) — CH2 + 2 C2 H5 OH 

 CO2 K CO2 K 



(2)/9CH, 



CO CH3 



CH CH 



CO2 C2 Hs CO2 C2H5+3 K0H=CH3 CO2 K + 



CH2 CH (CH3) + 2 C2 H5 OH 



CO2 K CO. K 



