92 F-J.] 



ACETIC ALDEHYDE 



177 



through isosuccinic (methylmalonic) 

 acid by the action of methyl iodide on 

 sodiomalonie ester (Ziibh'n, Ber. 12, 

 1 1 1 2,), and then as above under E. 



Or from malonic acid through ethyl- 

 ene by electrolysis (see under ethyl 

 alcohol [14; W]), and then as above 

 under A. 



[G-.] From succlnic acid [Vol. II] 

 through ethylene by electrolysis [14; 

 X], and then as under A. 



Or through dibromsuccinic acid by 

 bromination (Kekule, Ann. 117, 1 23 ; 

 Suppl. 1, 131 : see also under methane 

 [l ; T]), and the action of boiling water 

 on the dibromo-acid or its salts (Lossen 

 and Riebensahm, Ann. 292, 295; Lossen, 

 Ann. 30O, I; Lossen and Reisch, 

 Ibid. 5). 



Aldehyde is among the products of 

 electrolysis of potassium succinate (Peter- 

 sen, Zeit. physik. Ch. 33, 711). 



Or from succinic acid through acetyl- 

 enedicarboxylic acid (see under methane 

 [l; T]). The latter gives aldehyde (and 

 paraldehyde) on heating with water to 

 300 (Desgrez, Ann. Chim. [7] 3, 

 319). 



[EL] From lactic acid [Vol. II] by 

 oxidation with various oxidising com- 

 pounds (Liebig; Stadeler,Ann. 69, 332), 

 or by heating with dilute sulphuric 

 acid at 130 (Erlenmeyer, Zeit. [2] 4, 

 343). Also by electrolysis of a strong 

 solution of the potassium salt (Kolbe, 

 Ann. 113, 244; Brester, Zeit. [2] 2, 

 680; v. Miller and Hofer, Ber. 27, 

 468), or by the action of iodine on the 

 silver salt (Herzog and Leiser, Monats. 



22, 357)- 



Also from lactic acid through pyro- 

 racemic acid (see under benzyl alcohol 

 [54; P]), and then as under E. 



Or lactic ester can be converted into 

 lactic hydrazide by the action of hydra- 

 zine, and the hydrazide into the azide 

 by nitrous acid. The azide hydrolyses 

 to acetic aldehyde, &c. (Curtius and 

 Aufhauser, Ber. 34, 2796). 



Sarcolactic acid [Vol. II] gives acetic 

 aldehyde under similar conditions to 

 those which give rise to this aldehyde 

 from ordinary lactic acid (for electro- 

 lysis see v. Miller and Hofer, loc. cit.}. 



[I.] From tartaric or racemic acid 



[Vol. II] through pyroracemic acid 

 [54 ; N], and then as under E. 

 Aldehyde is among the products of the 

 distillation of tartaric acid (Volckel, 

 Ann. 89, 57). 



[J.] From glycerol [48] through 

 glyceric acid and pyroracemic acid 

 [54 ; F], and then as under E. 



Or from glycerol and potassium 

 cyanide [172] through allyl cyanide 

 [54; F] and /3-methylglyceric acid 

 (see under formic aldehyde [91 ; M and 

 J]). Acetic aldehyde is among the 

 products of electrolysis of potassium 

 6-methylglycerate (Pisarjevsky, Journ. 

 Russ. Soc. 29, 289). 



Or glycerol may be converted into 

 acrole'in [lOl] by dehydration (Redten- 

 bacher, Ann. 47, 1 20 ; Geuther and 

 Cartmell, Ann. 112, 2 ; Hiibner, Ann. 

 114, 35 ; Van Romburgh, Bull. Soc. [2] 

 36, 549 ; Wagner, Journ. Russ. Soc. 

 16, 317 ; Griner, Ann. Chim. [6] 26, 

 367; Aronstein, Ann. Suppl. 3, 180; 

 Fischer, Ber. 20, 3388; Wohl and 

 Neuberg, Ber. 32, 1352 ; Wohlk, Journ. 

 pr. Ch. [2] 61, 2co), acrylic acid by 

 oxidation of the latter (Redtenbacher,foc. 

 cit. 125; Glaus, Ann. Suppl. 2, 123), 

 and /3-chlorlactic acid by the addition 

 of hypochlorous acid to acrylic acid 

 (Melikoff, Journ. Russ. Soc. 13, 157). 

 /3-Chlorlactic acid gives aldehyde as 

 above under E. 



Or acrole'm and ethyl alcohol [14] com- 

 bine under the influence of hydrogen 

 chloride to form /3-chlorpropionacetal 

 (Wohl, Ber. 21,6i8; 81,1796). The latter 

 is converted by the action of alkali into 

 the /3-hydroxy-acetal, and this by oxida- 

 tion with potassium permanganate gives 

 ^3-diethoxypropionic acid. The latter, 

 on heating with dilute sulphuric acid at 

 50, yields the semi-aldehyde of malonic 

 acid, which is resolved above 50 

 into carbon dioxide and acetic alde- 

 hyde (Wohl and Emmerich, Ber. 33, 

 2760). 



Or from glycerol through glyceric 

 acid, a-chlorlactic acid by the action of 

 hydrochloric acid on the latter (Werigo 

 and Melikoff, Ber. 12, 178), oxyacrylie 

 (glycidic) acid by the action of alcoholic 

 potash (Melikoff, Ber. 13, 271 ; Journ. 

 Russ. Soc. 13, 2ii), /3-chlorlactic acid 



