APPENDIX 



289 



1O5. Citronellal (p. 192). 



The formula assigned to this com- 

 pound on p. 192 has been confirmed 

 (Barbier and Leser, Comp. Rend. 124, 

 1308; Harries and Roder, Ber. 32, 

 3363 : see also the note on p. 192). It 

 is therefore 2 : 6-dimethyl-i-octenal-8, 

 and is the aldehyde of d-citronellol [38, 

 p. 89, and this appendix]. For occur- 

 rence in oil of lemon and of lemon-grass 

 see further Tiemann, Ber. 32, 812; 

 834 : compare also Stiehl, Journ. pr. 

 Ch. [2] 58, 62. 



To be added to synthetical pro- 

 cesses : 



[B, p. 192.] From d-citronellol [38] 

 by oxidation with chromic acid mixture 

 (Tiemann and Schmidt, Ber. 30, 34). 



106. Acetone (p. 192). 



Acetone is said to be present in 

 normal horse urine (Kiesel, Pfliiger's 

 Arch. 97, 480). Acetone occurs in the 

 expired air and in the urine of man 

 only in grave cases of diabetes (Le 

 Golf, Comp. Rend. 137, 216). Acetone 

 has been found in the fluid from a pan- 

 creatic cyst (Alay and Rispal, Journ. 

 Pharm. [6] 17, 319). 



To be added to synthetical pro- 

 cesses : 



[B, p. 193.] Isopropyl alcohol is 

 readily converted into acetone by pass- 

 ing the vapour over reduced copper 

 heated to 250-430. At 300 platinum 

 sponge acts in a similar way. Reduced 

 nickel is less effective (Sabatier and 

 Senderens, Comp. Rend. 136, 983). 



A small quantity of acetone is 

 formed when the vapour of propylene 

 oxide is passed over aluminium oxide 

 heated to 200 (Ipatieff and Leonto- 

 witsch, Ber. 36, 2016). 



[K, p. 196.] A solution of sodium 

 isobutyrate gives acetone when electro- 

 lysed in presence of sodium chlorate 

 (Moest, Germ. Pat. 138442 of 1902; 

 Journ. Ch. Soc. 84, I, 546). 



[V, p. 199.] Methylheptenone gives 

 acetone among other products on oxida- 

 tion by ozone (Harries, Ber. 36, 1933). 



113. Diacetyl (p. 203). 



To be added to synthetical pro- 

 cesses : 



[B, p. 203.] Oxalic ester and magne- 

 sium methiodide interact in ethereal 

 solution to form a small quantity of 

 diacetyl (Gattermann and Maffezzoli, 

 Ber. 36, 4152). 



114. Benzole Aldehyde (p. 205). 



To be added to synthetical pro- 

 cesses : 



[A, p. 205.] Toluene, on passing the 

 vapour over heated lead oxide, gives 

 stilbene = symmetrical diphenylethylene 

 (Behr and Van Dorp, Ber. 6, 754 ; 

 Lorenz, Ber. 7, 1096; 8, 1455), or 

 benzal chloride gives stilbene on treat- 

 ment with sodium or zinc dust in 

 appropriate solvents (Limpricht, Ann. 

 139, 318; Lippmann and Hawliczek, 

 Jahresber. 1877, 405). Stilbene gives 

 benzoic aldehyde among other products 

 on oxidation with chromic acid mixture. 

 By photochemical oxidation stilbene 

 yields benzoic aldehyde as an inter- 

 mediate product (Ciamician and Silber, 

 Ber. 36, 4266). 



Benzene and formic acid [Vol. II] 

 give benzoic aldehyde by the inter- 

 action of phenyl magnesium bromide 

 (from brombenzene and magnesium) 

 and formic ester in ethereal solution 

 (Gattermann and Maffezzoli, Ber. 36, 

 4152). 



[B, p. 208.] By the action of nitrous 

 gas on styrene in ethereal solution 

 a ' pseudonitrosite ' is formed. This 

 gives benzoic aldehyde among the pro- 

 ducts of decomposition by hot aqueous 

 alkali or by sodium ethoxide solution 

 (Wieland, Ber. 36, 2558). 



[C, p. 209.] Benzamide and magne- 

 sium methiodide interact to form a 

 compound which is decomposed by 

 water with the formation of aceto- 

 phenone (Be"is, Comp. Rend. 137, 575). 



NOTE : This synthesis affects all products 

 of which acetophenone is a generator, e. g. 

 methylphenyl carbinol [58 ; C, p. 118.] 



[D, p. 209.] For production of benzoic 

 aldehyde by the electrolysis of a solu- 



