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, CH 2 CO 2 H 



CH 2 



CH 2 CO 2 H, is produced. Methyl-aceto-glutaric 

 ester, formed similarly from sodmethylacetoacetic ester boils at 280- 

 281 and has a specific gravity of 1.043 at 2O When this is saponified 

 potassium methyl-glutarate CH (CH 3 ) CO 2 K 



CH 2 



CH 2 CO 2 K is produced which is a crystal- 

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



KRESSNER, G., 1878. 



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



Chem. 1878, 721. 



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



Ester. 



a-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 

 CH 3 

 CO 



C (CH 3 )- -CH 2 

 C0 2 C 2 H 5 , C0 2 C 2 H 5 + 3 KOH=CH 3 CO 2 K+ 



CH (CH 3 ) CH 2 -f 2 C 2 H 5 OH 

 CO 2 K C0 2 K 



CO CH 3 



CH CH 



C0 2 C 2 H 5 C0 2 C 2 H 5 +3 KOH=CH 3 CO 2 K+ 



CH 2 -- CH (CH 3 ) + 2 C 2 H 5 OH 



CO a K CO 2 K 



