40 ELECTROLYSIS AND ELECTROS YN THESIS 



2C,H 6 COO - = C a H 4 + CO, + C 2 H B COOH, 

 2C 2 H 6 OOC.CH 2 CH,.COO - = 2C 2 H 5 OOC.CH 2 

 -CH 2 .CH : CH 3 +C 2 H 6 OOC.CH 2 .CH 9 .COOH+CO a . 



In this way it was possible to isolate methyl-acrylic 

 acid by the electrolysis of ethyl-potassium dimethyl- 

 malonate, and ethyl-crotonic acid by electrolyzing a 

 solution of the ethyl-potassium salt of diethyl-malonic 

 acid. On the electrolysis of sebacic acid the ethyl 

 ester of an unsaturated acid, CH 9 : CH(CH 2 ) 6 .COOH, 

 was formed. 



Brown and Walker 1 also electrolyzed the sodium- 

 ethyl salt of camphoric acid and obtained two esters 

 which they were able to separate by means of frac- 

 tional distillation. One of these (boiling-point 212- 

 213) on being saponified yielded an unsaturated 

 monobasic acid, C 9 H 14 O 2 , campholytic acid ; the other, 

 having a higher boiling-point (240-242), was the 

 neutral ester of a dibasic acid, C 18 H 30 O 4 , to which 

 Walker gave the name of camphothetic acid. The 

 experiments are of great importance, because they 

 prove the dibasic nature of camphoric acid, a fact 

 which is doubted by Friedel. 



Walker and Henderson 5 found, moreover, that 

 upon the electrolysis of concentrated aqueous solu- 

 tions of the potassium salt of allocamphoric ester there 



1 Lieb. Ann., 274, 71. 



1 Journ. Chem. Soc., 67, 337. 



