186 ALDEHYDES AND KETONES : FATTY GROUP [96ZZ/B-F. 



droxide (Belohoubek, Ber. 12, 1872; 

 Morley and Green, Trans. Ch. Soc. 47, 

 132) and the action of acidified water 

 on the glycol at 215 (Linnemann, Ann. 

 192, 6 1 : see also Lieben, Monats. 23, 

 60), or by heating with zinc chloride 

 (Flawitzky, Ber. 11, 1256 ; Journ. Russ. 

 Soc. 10, 348), by which propanal is 

 formed. 



Or from glycerol through acrole'in 

 [lOl], which, on treatment with potassium 

 cyanide [172] and acetic acid, gives the 

 nitrile or vinylglycollic = i : 3-butenolic 

 acid and the acid itself on hydrolysis. 

 The latter combines with bromine to 

 form 4:3: 2-dibrombutanolic acid, and 

 this is reduced by sodium amalgam to 

 a-hydroxybutyric acid (Van der Sleen, 

 Rec. Tr. Ch. 18, 302 ; 21, 209). Subse- 

 quent steps as below under N. 



[C.] From citric acid [Vol. II] through 

 citraconic acid (see under benzyl alcohol 

 [54; M]). The latter combines with 

 bromine to form citradibrompyrotartaric 

 acid (Kekule", Ann. Suppl. 2, 96 ; Fittig 

 and Krusemark, Ann. 206, 2), and this 

 on heating with alkali gives propanal 

 (Friedrich, Ann. 203, 355 ; Fittig and 

 Krusemark, loc. cit. 4; Ssemenoff, Journ. 

 Russ. Soc. 31, 296), which can be con- 

 verted into methylethylacrole'in, &c., as 

 under A. 



Citraconic acid gives mesaconic acid 

 under the influence of acids, alkalis, or 

 water (Gottlieb, Ann. 77, 268 ; Kekule, 

 Ann. Suppl. 2, 94; Fittig, Ann. 188, 

 77,80; Delisle, Ann. 269, 82; Swarts, 

 Jahresber. 1873, 579), and this com- 

 bines with bromine to form mesadi- 

 brompyrotartaric acid (Kekule, loc. cit. 

 102), which also yields propanal among 

 the products of its decomposition by 

 alkalis (Fittig and Krusemark, loc. cit. 4). 



Or citric acid by distillation, or by 

 heating with dilute sulphuric acid, gives 

 itaconic acid (Baup, Ann. 19, 29 ; 

 Markownikoff and Purgold, Zeit. [2] 

 3, 264), which combines with hydrogen 

 chloride to form itachlorpyrotartaric 

 acid (Swarts, Zeit. [2] 2, 721 ; Michael, 

 Journ. pr. Ch. [2] 45, 60). The latter 

 on treatment with water or alkalis 

 yields itamalic (hydroxymethylsuccinic) 

 acid, which readily passes into its an- 

 hydride, paraconic acid (Swarts, Zeit. 



[2] 3, 648 ; Beer, Ann. 216, 84), and 

 this gives citraconic anhydride on dis- 

 tillation. 



Or from citric acid through acetone- 

 dicarboxylic, /3-oxyglutaric, vinylacetic, 

 and crotonic acid (see under n-propyl 

 alcohol [15 ; W]). From crotonic acid 

 as under N below. 



[D.] From lactic acid [Vol. II] 

 through citraconic acid by distillation 

 (Engelhardt, Ann. 70, 243 ; 246), and 

 then as above. Or through pyroracemic 

 acid and pyrotartaric acid (see under 

 benzyl alcohol [54 ; P and I]), and then 

 as below under I and above under C. 



[E.] From acetoacetic acid (ester) 

 [Vol. II] and hydrogen cyanide [172] 

 through hydroxypyrotartaric and citra- 

 conic acid (see under benzyl alcohol 

 [54; M, note]), and then as above 

 under C. Or from acetoacetic ester 

 and a-brompropionic ester through /3- 

 methylacetosuccinic ester and pyrotar- 

 taric acid (see under benzyl alcohol 

 [54; I]). Or from chloracetic ester 

 and acetoacetic ester through aceto- 

 succinic ester, a-methylacetosuccinic 

 ester, and pyrotartaric acid (Ibid.). Or 

 from acetoacetic ester through isonitroso- 

 acetone, acetyl cyanide, pyroracemic and 

 pyrotartaric acid (Ibid.). 



Or from acetoacetic ester through 

 methylacetoacetic ester by the action 

 of methyl iodide on the sodium deriva- 

 tive of acetoacetic ester ; methylaceto- 

 acetic ester on successive treatment 

 with bromine and alcoholic potash gives 

 mesaconic ('oxytetric ') acid (Demar^ay, 

 Ann. Chim. [5] 20, 473 ; Gorboff, 

 Journ. Russ. Soc. 19, 605 ; Cloez, 

 Bull. Soc. [3] 3, 598 ; 602 : see also 

 under benzyl alcohol [54 ; I]), and this 

 can be converted into propanal, &c., as 

 under C. 



Or from acetoacetic ester through 

 the y-bromo-derivative, succinylsuccinic 

 ester, and ethyl malonic acid (see under 

 n-propyl alcohol [15 ; A A ; Y ; O]). 

 From the latter as below under G-. 



Or from ethylacetoacetic ester through 

 I : i-dinitropropane and propanal as 

 under n-propyl alcohol [15 ; A A]. 



[F.] From isovaleric acid [Vol. II] 

 through hydroxypyrotartaric acid, citra- 

 conic acid, &c. [54; M]. 



