70 F-I.] 



by bromination and subsequent removal 

 of hydrogen bromide (Merling, Ann. 

 278, 38; Vorlander, Ber. 28, 2348; 

 Ann. 294, 269). 



Or the glycerol may be converted into 

 allyl bromide and trimethylene bromide 

 (see under n-propyl alcohol [15 ; E]). 

 The latter interacts with sodio-acetoace- 

 tic ester to form brompropylacetoacetic 

 ester (Lipp, Ber. 18, 3279), which gives 

 acetylbutyl alcohol on heating with 

 dilute hydrochloric acid (Ibid. 3280; 

 Col man and W. H. Perkin, junr., Trans. 

 Ch. Soc. 55, 354). The alcohol yields 

 y-acetobutyric acid on oxidation with 

 chromic acid mixture. 



Or from ethyl alcohol through iodo- 

 form and methylene iodide [14; I, p. 55] 

 and the action of the latter on sodio- 

 acetoacetic ester, which gives a product 

 (consisting of two methylketohexenyl- 

 enecarboxylic esters, C 10 H 14 O 3 ) which, 

 on boiling with dilute sulphuric acid, 

 yields methyl-i-cyclohexenone-3. The 

 latter on oxidation with alkaline per- 

 manganate gives y-acetobutyric acid 

 (Hagemann, Ber. 26, 876, &c.; Harries, 

 Ber. 35, 1176 : see also Hagemann and 

 Knoevenagel, Ann. 297, 138). Subse- 

 quent steps as above. 



The glycerol in the above synthesis 

 might be replaced by lactic acid [Vol. 

 II], which gives acrylic acid (among 

 other products) when the calcium salt 

 is heated (Glaus, Ann. 136, 288 : for 

 production of acrylic acid from lactic 

 acid via a-chlorpropionic acid see Michael 

 and Garner, Ber. 34, 4050). Ethyl 

 acrylate condenses with sodio-acetoacetic 

 ester to form acetoglutaric ester (Vor- 

 lander, Ber. 28, 2349), which can be 

 converted into y-acetobutyric acid, &c., 

 as above. 



Or succinic ac [Vol. II] gives /3- 

 iodopropionic acii by electrolysing the 

 sodium salt with potassium iodide for 

 the negative electrolyte (v. Miller and 

 Hofer, Ber. 28, 2436). /3-Iodopropionic 

 acid and acetoacetic ester give y-aceto- 

 butyric acid and resorcinol as above. 



Or the glycerol may be replaced by 

 acetic aldehyde [92], which on chlorina- 

 tion gives butyrochloral =2:2: 3-tri- 

 chlorbutanal (Kramer and Pinner, Ber. 

 3, 383 ; Pinner, Ann. 179, 26). The 



RESORCINOL 



145 



latter on heating with potash solution 

 gives an allylene dichloride (C 3 H 4 CL 2 ), 

 which on heating with water yields 

 acrylic acid (Pinner, Ber. 7, 66). Sub- 

 sequent steps as above. 



NOTE : Propionic acid [Vol. II] gives eta- and 

 a#-dibromo-acid (see under benzyl alcohol [54 ; 

 O]). The a/3-acid yields acrylic acid on treating 

 the solution with zinc and sulphuric acid 

 (Caspaiy and Tollens, Ann. 167, 241 ; Melikoff, 

 Journ. Russ. Soc. 13, 156). 



The propyl alcohols [15 ; 16] also give acrylic 

 acid through propylene and acrolem [101] (see 

 under benzyl alcohol [54 ; E]), and mannitol 

 [51] gives acrolei'n among the products of its 

 oxidation by manganese dioxide and sulphuric 

 acid (54 ; AA). 



[G.] Euxanthone [136] gives resor- 

 cinol among the products of fusion with 

 potash. 



[H.] From furfural [126] and acetone 

 [106] through pyromucic acid, muco- 

 bromic acid, and nitromalonic alde- 

 hyde (see under phloroglucinol [86 ; I]). 

 The latter condenses with acetone in 

 the presence of alkali to form p-nitro- 

 phenol (Hill and Torrey, Ber. 28, 2598 ; 

 Am. Ch. Journ. 22, 89). Subsequent 

 steps as above under C. 



[I.] From malonic and citric acids 



EVol. II] and alcohol [14]. Chloroform 

 1 ; D, &c.] reacts with sodium ethoxide 

 to form orthoformic triethyl ester 

 (Williamson and Kay, Ann. 92, 346; 

 Stapff, Zeit. [2] 7, 186; Deutsch, Ber. 

 12, 1 1 6 ; Wichelhaus and Ladenburg, 

 Ann. 152, 164; Arnhold, Ann. 240, 

 1 93). This ester condenses with diethyl 

 malonate (acetic anhydride as condens- 

 ing agent) to form ethoxymethylene- 

 malonic ester (Claisen, Ber. 26, 2729). 

 The latter condenses with acetonedi- 

 carboxylic ester (from citric acid; see 

 under glycerol [48; M]) under the 

 influence of sodium ethoxide to form 

 acetonedicarboxylmethenylmalonic ester, 

 which undergoes further condensation 

 with the elimination of alcohol and the 

 formation of resorcinoltricarboxylic ester 

 (dihydroxytrimesic ester). The latter 

 on boiling with sodium hydroxide solu- 

 tion gives resorcinoldicarboxylic = /3- 

 dihydroxybenzoic acid (Errera, Gazz. 

 31, 139; Ch. Centr. 1901, 1, 1092). 

 The acid yields resorcinol on heating 

 (Senhofer and Brunner, Ber. 13, Ref. 



93)- 



