110 



AROMATIC ALCOHOLS AND PHENOLS [54 P-H. 



denhauer, Ann. 131, 337 ; 339 ; Bot- 

 tinger, Ann. 196, 92), which can be 

 treated as above. Glyceric acid also 

 gives among the products of its dis- 

 tillation (with acid potassium sul- 

 phate) pyroracemic acid (Moldenhauer, 

 Ann. 131, 337; Bottinger, Ann. 196, 92), 

 which can be converted into uvitic acid, 

 &c., as under I. (For preparation of 

 gly eerie acid from glycerol by oxidising 

 with nitric acid in presence of red lead 

 see Zinno, Ch. Centr. 1898, 1, 26 ; also 

 Wohlk, Journ. pr. Ch. [2] 61, 200 : by 

 alkaline silver chloride, Cazeneuve, Bull. 

 Soc. [3] 15, 763.) 



Or from glycerol through epichlor- 

 hydrin by the action of hydrochloric 

 acid (Berthelot, Ann. 92, 302 ; Ann. 

 Chim. [3] 41, 299 ; Hiibner and Miiller, 

 Zeit. [2] 6, 344 ; Watt, Ber. 5, 257 ; 

 Reboul, Ann. Suppl. 1, 22 1 ; Tollens 

 and Miinder, Zeit. [2] 7, 252 ; Prevost, 

 Journ. pr. Ch. [2] 12, 160 ; Glaus, Ber. 

 10, 557 ; Cloez, Ann. Chim. [6] 9, 145). 

 Epichlorhydrin condenses with hydrogen 

 cyanide [172] to form a nitrile which 

 gives crotonic acid on reduction with 

 hydriodic acid (Lespieau, Comp. Rend. 

 127, 965 ; 129, 224). 



Or from glycerol through acrole'in 

 [lOll (see under mannitol [51 ; B]), 

 acrylic acid (Wohlk, Journ. pr. Ch. [2] 

 61, 200), a-chlorlactic, glyceric, pyro- 

 tartaric acids, and allylene as above under 

 E. Or from acrole'in through /3-chlor- 

 propionic aldehyde and acid and acrylic 

 acid (Geuther and Cartmell, Ann. 112, 

 3; Krestownikoff, Jahresber. 1880,696; 

 Wohlk, loc. cit.}. 



Or from glycerol through allyl alco- 

 hol (see under ethyl alcohol [14 ; G]), 

 o/3-dibrompropyl alcohol, a/3-dibrom- 

 propionic acid and acrylic acid (Biil- 

 mann and Wohlk, Journ. pr. Ch. [2] 

 61, 199 ; 215), and then as above. Or 

 from a/3-dibrompropionic acid to gly- 

 ceric acid as under O below. Or from 

 allyl alcohol through glyoxal (172 ; 

 BB), and, by means of hydrogen cyanide 

 [172], the nitrile of pyroracemic acid as 

 below under H. 



[G.] Malonic acid [Vol. II], paralde- 

 lyde (by polymerisation of acetaldehyde 

 [92]), and glacial acetic acid [Vol. II] 

 when heated to 100 give a-crotonic 



(2-butenoic) acid (Komnenos, Ann. 218, 

 149). The latter combines with hypo- 

 chlorous acid to form a-chlor-/3-hydroxy- 

 butyric acid (Erlenmeyer and Miiller, 

 Ber. 15, 49; Melikoff, Ann. 234, 198). 

 This acid on heating with strong aqueous 

 hydrochloric acid at 100 gives a/3-di- 

 chlorbutyric acid (Melikoff, loc. cit. 

 301), which, by heating with excess of 

 aqueous alkali, yields a-chlorisopropyl- 

 ene (Wislicenus, Ann. 248, 297). The 

 latter on heating with alcoholic potash 

 gives allylene which can be treated as 

 above. 



Or crotonic acid (ester) is condensed 

 by sodium ethoxide to form dicrotonic 

 ester from which the acid can be ob- 

 tained by hydrolysis. Dicrotonic acid 

 gives on oxidation with alkaline per- 

 manganate methylsuccinic = pyrotar- 

 taric acid (v. Pechmann, Ber. 33, 3323), 

 which can be converted into allylene, 

 &c., as under N below. 



Or malonic acid (ester) can be con- 

 verted into methylmalonic ester by 

 sodium and methyl iodide. The sodium 

 derivative of methylmalonic ester inter- 

 acts with ethyl chloracetate to form 

 a propanetricarboxylic ester, the acid 

 ( = a-methylethenyltricarboxylic acid) 

 from which gives pyrotartaric acid on 

 hydrolysis (Bischoff and Kuhlberg, Ber. 

 23, 635). 



Or from diethyl malonate, aldehyde, 

 and acetic anhydride through ethyli- 

 denemalonic ester, /3-cyanobutyric acid, 

 and pyrotartaric acid (see under n-propyl 

 alcohol [15 ; T]). 



[H.] Acetic aldehyde [92] by the action 

 of chlorine gives butyrochloral = 2 : 2 : 

 3-trichlorbutanal (Kramer and Pinner, 

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

 which, by oxidation with nitric acid, 

 yields aa/3-trichlorbutyric acid (Kramer 

 and Pinner, loc. cit. 389 ; Judson, Ber. 

 3,785; Garzarolli ! Ann.l82,i8i). The 

 latter on reduction with zinc and water 

 (Sarnoff, Ann. 164, 93) gives a-chlor- 

 crotonic acid, which, by heating with 

 aqueous hydrochloric acid, yields a/3- 

 dichlorbutyric acid (Merlikoff, Ann. 

 234, 201). The latter can be converted 

 into allylene, &c., as under G. 



cia/3-Trichlorbutyric acid also decom- 

 poses on heating the aqueous solution 



