36 ELECTROLYSIS AND ELECTROS YN THESIS 



The alkali salts of oxyacids give, in addition to the 

 above, many other substances, principally aldehydes, 

 and the results are the same even if the attempt is 

 made to weaken the action of the electrolytic oxygen 

 by converting the alcohols into esters. 



Thus from the sodium salt of glycolic acid (CH,OH. 

 COOH), ethyl-glycolic acid (CH.OC.H..COOH), and 

 a-lacttc acM (CH 9 .CH(OH)COOH) the chief product 

 obtained is acetic aldehyde, and it is quite possible that 

 the production of hydrobenzom and isohydrobenzom 

 from mandelic acid is due to the electrolytic reduction 

 of the benzaldehyde originally formed. 



This view is supported by the investigations of 

 Kauffmann, 1 who actually obtained hydrobenzom and 

 isohydrobenzoin by the direct electrolytic reduction 

 of benzaldehyde. 



Elbs 3 emphasizes the fact that it is not necessary 

 to suppose that aldehydes are a result of secondary 

 oxidation produced by the oxygen available in the 

 region of the anode, but that their formation can also 

 be regarded as analogous to that of ethylene from 

 propionic acid: 

 2CH 3 .CH a .COO - = CH 3 .CH 2 .COOH 



2CH 3 .CH(OH)COO - = CH 3 .CH(OH).COOH 



CH 3 .CHO. 



1 Ztschr. f. Elektroch., 2, 367. 

 8 Jahrbuch. d. Elektroch., 3, 295. 



