224 



AROMATIC ALDEHYDES AND KETONES [125-126 A. 



125. Asaryl Aldehyde ; 



2:4: 5-Trimethoxybeiizoic Aldehyde ; 



2:4: 5-Phenetriolmethylal 



Trimethyl Ether. 



CHO 



O.CH, 



CH,.0 



O.CH, 



NATURAL SOURCE. 



The complex, if not the free aldehyde, 

 occurs with asarone [89] in oil of Acorus 

 calamus (Thorns and Beckstroem, Ber. 

 34, 1021; 35, 3188). 



SYNTHETICAL PROCESSES. 



[A.] From asarone [89] by oxidation 

 with chromic acid or potassium per- 

 manganate and sulphuric acid (Butleroff 

 and Rizza, Journ. Russ. Soc. 19, 3). 



[B.] From liydroxyquinol [85], methyl 

 alcohol [13], and hydrogen cyanide [172]. 

 The trimethyl ether of hydroxyquinol 

 is treated in benzene solution with hy- 

 drogen cyanide and hydrogen chloride 

 in the presence of dry aluminium 

 chloride, and the product decomposed 

 by cold water (Gattermann and Eggers, 

 Ber. 32, 289). 



126. Furfural; Furfurol ; 



Fyromucic Aldehyde ; 

 Furaiicarboxylic Aldehyde. 



-CH 



HC- 



HC 



C.CHO 



O 



NATURAL SOURCES. 



Furfural has been found in oil of 

 cloves (SchimmeFs Ber. Oct. 1896 ; 

 Ch. Centr. 1896, 2, 977 ; E. Erdmann, 

 Journ. pr. Ch. [2] 56, 154; SchimmeFs 

 Ber. April, 1897 ; Gerber, Mon. Sci. 

 [4] 11, 880), in the distillation water 

 from oil of caraway and oil of ambrette 

 seeds from Hibiscus abelmoschus (Schim- 

 meFs Ber. Oct. 1899 ; Ch. Centr. 1899, 



2, 880). Also in the distillation water 

 from vetiver oil from Andropogon muri- 

 catus, E. and W. Indies, Brazil, &c. 

 (Ibid. April, 1900; Ch. Centr. 1900, 



1, 907), and from oil of bay (Ibid. April, 

 1901). 



Ceylon oil of cinnamon contains fur- 

 fural (SchimmeFs Ber. April, 1902 ; 

 Walbaum and Hiithig, Journ. pr. Ch. 

 [2] 66, 47)- 



The aldehyde is contained also in 

 petit-grain oil from Paraguay (Schim- 

 meFs Ber. Oct. 1902 ; Ch. Centr. 1902, 



2, 1208), in the cohobation water of 

 savin oil from Juniperus sabina, and in 

 the distillation water of W. Indian 

 sandal-wood oil (Ibid. April, 1903 ; Ch. 

 Centr. 1903, 1, 1086). 



Furfural has been found in brandy, 

 in certain fusel oils, in malt wort, and 

 beer (Morin, Comp. Rend. 105, 1019 ; 

 Udranszky, Zeit. physiol. Ch. 13, 248 ; 

 Forster, Ber. 15, 230 ; 322 ; Brand, 

 Journ. Fed. Inst. 4, 562 ; Windisch, 

 Ibid. 561 ; Heim, Ibid. 563). 



According to Van Laer the furfural 

 found in the secondary products of 

 alcoholic fermentation is not of bio- 

 chemical origin, but due to subsequent 

 decomposition of furfural-yielding com- 

 pounds (Journ. Fed. Inst. 4, 2). This 

 may be true also of the furfural found 

 in the above plant oils. 



SYNTHETICAL PROCESSES. 



[A.] From dextrose [154] by heating 

 with dilute acids (Berthelot and Andre, 

 Comp. Rend. 123, 567). It has long 

 been known that sugars and other 

 carbohydrates yield furfural on dry 

 distillation or on heating with dilute 

 acids (Dobereiner, Ann. 3, 141 ; Volckel, 

 Ann. 85, 65; Forster, Ber. 15, 230; 

 322 ; Stenhouse, Phil. Mag. [3] 18, 

 122; 37, 226; Fownes, Phil. Trans. 

 1 845, 253 ; Cahours, Ann. Chim. [3] 

 24, 277 ; Emmet, Am. Journ. Sci. 32, 

 140; Gudkoff, Zeit. [2] Q, 362; 

 Guyard, Bull. Soc. [2] 41, 289 ; Scruff, 

 Ber. 20, 540; Ann. 239, 382; Stone 

 and Tollens, Ann. 249, 237). 



[B.] Mannose [156] gives furfural on 

 heating with water at 140 (Fischer 

 and Hirschberger, Ber. 22, 369). 



