204 



ALDEHYDES AND KETONES: FATTY GROUP [113-O. 



1899, 2, 880), from vetiver oil from 

 Andropogon muricalus, E. and W. Indies, 

 Brazil, &c. (Ibid. April, 1900 ; Ch, 

 Centr. 1900, 1, 907), and from oil of 

 bay (Ibid, April, 1901), Occurs also 

 in the lower boiling-point fraction of 

 oil of savin from Juniperus sabina (Ibid. 

 Oct. 1900; Ch. Centr. 7900, 2, 970), 

 in the cohobation water of the same 

 oil, and in the distillation water of 

 W. Indian sandal-wood oil (Ibid* April, 

 1903; Ch. Centr. 1903, 1, 1086). 



NOTE : It has not yet been proved that 

 diacetyl pre-exists ready formed in these oils. 



SYNTHETICAL PROCESSES. 



[A.] From methyl alcohol [13] and 

 acetoacetic ester [Vol. II] through 

 isonitrosomethylethyl ketone, &c., or 

 through acetosuccinic ester, &c., as 

 under quinol [71; O]. Or through 

 y-brom-methylacetoacetic ester and 

 tetrinic acid, or through laevulic acid 

 (Ibid.}. Or through pyroracemic acid, 

 &c. (Ibid. DD). 



Or from methyl alcohol and aceto- 

 acetic ester through methylethyl ketone 

 (methylaeetyl carbinol [44 ; B])< The 

 ketone is converted into the isonitroso- 

 derivative by the action of amyl nitrite 

 in presence of sodium ethylate or 

 hydrogen chloride according to the 

 method of Claisen and Manasse (Ber. 

 20, 656; 2194; 22, 526; Kalischer, 

 Ber. 28, 1518; Diels and Jost, Ber. 

 35, 3290). From the isonitroso- ketone 

 = diacetylmonoxime as under quinol 

 [71; O]. 



NOTE : All generators of methylethyl ketone 

 given under methylaeetyl carbinol [44] thus 

 become generators of diacetyl. 



[B.] From oxalic and acetic acids 

 [Vol. II] and alcohol [14] through 

 ketipic acid, &c. [71 ; S]. 



[C.] From dextrose [154], tavulose 

 [155], or mannose [156] through laevulic 

 acid (see under erythritol [50; H; I ; J] 

 and quinol [71 ; O]). 



[D.] From glycerol [48] and acetic or 

 m atonic acid [Vol. II] through laevulic 

 acid (erythritol [5O ; P ; G]). Or 



from glycerol through glyceric and 

 pyroracemic acids (quinol [71 ; X]) ; or 

 from glycerol and acetoacetic ester 

 through allylacetone and laevulic acid 

 (erythritol [50 ; GJ). 



[E.] From hydrogen cyanide [172] and 

 acetic acid [Vol. II] through pyro- 

 racemic acid (quinol [71 ; DD]). Or 

 from hydrogen cyanide and ethyl alcohol 

 [14] through pyroracemic acid (Ibid. 

 CC). 



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

 through laevulic acid (erythritol [50 ; 

 E]). 



[G.] From acetic aldehyde [92] 

 through Isevulie acid (erythritol [50 ; 

 N]). Or from aldehyde and zinc ethyl 

 through secondary butyl alcohol = 2- 

 butaiiol (secondary butyl mustard oil 

 [165 ; D]). The secondary alcohol gives 

 diacetyl when oxidised by nitric acid 

 (Ponzio, Gazz. 31, 401). 



NOTE : The generators of secondary butyl 

 alcohol given under secondary butyl mustard 

 oil thus become generators of diacetyl. These 



are : methyl [13] ; ethyl [14] ; normal and isobutyl 

 alcohols [1? ; 18] ; erythritol [50] ; formic acid ; 

 isovaleric acid ; acetoacetic ester ; and all generators 

 of methylethyl ketone. 



[H.] From n-propyl [15] or isopropyl 

 alcohol [16] through propylene and 

 pyroracemic acid (quinol [71; HH]). 



NOTE : All generators of propylene thus 

 become, through pyroracemic acid, generators 

 of diacetyl. 



[I.] From acetone [106] and ethyl 

 acetate through acetylacetone and Isevu- 

 lic acid (erythritol [50 ; G]). 



[J.] From methylheptenone [ill] 

 through laevulic acid (erythritol [50 ; 



Q])- 



[K.] From dimethylheptenol [35] 

 through Isevulic acid (Ibid. N"). 



[L.] From propionic acid [Vol. II] 

 through pyroracemic acid (quinol [71 ; 

 FP]). 



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

 through pyroracemic acid (Ibid. GG). 



[N.] From tartar ic or racemic acid 

 [Vol. II] through pyroracemic acid 

 (Ibid. BB). 



[O.] From citric acid [Vol. II] 

 through pyroracemic acid (Ibid. EE). 



