— 151 — 



Aldehydes. 



In the electrolytic reduction of aromatic aldehydes, 

 H. D. Law 1 ) obtained compounds of the hydrobenzoin type. The 

 reduction is accomplished according to the equation 2R»CHO-)-2H 

 = R.CH(OH).CH(OH).R. The introduction of — OH-, — OCH 3 - 

 and = 2 CH 2 - groups has no influence on the reaction. In the 

 experiments the anode and cathode compartments were separated by 

 a diaphragm. The excess of hydrogen evolved in the cathode compart- 

 ment was collected in the usual manner, and the intensity of the current 

 was moreover measured with a hydrogen coulombmeter. Bodies which 

 could in this manner be reduced without difficulty, were cuminaldehyde, 

 piperonal, vanillin, anisaldehyde, salicylaldehyde; further, anisoin, cuminoin, 

 and piperonyloin. The mixtures of the hydro- and isohydrobenzoins 

 formed can in every case be separated. 



Unsaturated aldehydes, such as furfurol and cinnamaldehyde, yielded 

 only resins on electrolytic reduction. 



Ketones. 



We have already referred 2 ) to the synthesis of the three menthanones 

 (m-menthanone-2,-3, and -4) perfected by A. Kotz and his collabor- 

 ators. The crude material for these experiments is o-, m- and p-cresol, 

 which were transformed over the corresponding methylcyclohexanones 

 and their oxalic and carboxylic esters, finally into the methyl isopropyl 

 cyclohexanone carboxylic esters. 



In a quite analogous manner A. Kotz and A. Mich els 3 ) have 

 now, starting from phenol, produced isopropyl- 1 -cyclohexanone -2, 

 after having first obtained cyclohexanone - 2 - oxalic ester and the corre- 

 sponding carboxylic ester. Isopropyl - 1 - cyclohexanone - 2 (by splitting 

 the ketone from the corresponding carboxylic ester), boils at 92 ° 

 (15 mm. pressure); its semicarbazone melts at 187 . With regard 

 to the production of methyl- 1 -isopropyl- 3- hexanone- 2, (m-menthan- 

 one-2, m-menthone) from the diester, we refer to our last Report, 

 p. 148, as the methods are analogous. 



A. Kotz 4 ) also makes a communication regarding the experiments 

 for producing dicarboxylic esters from cyclic monoketones. Such esters 

 are generally formed by conversion of chloro -formic ester or chloro- 

 acetic ester, with the sodium compounds of cyclic /5-ketonic acid esters. 

 Some esters of this class were produced by Kotz and Mich els in the 



x ) Journ. chem. Soc. 89 (1906), 1512. 



2 ) Report April 1906, 126; October 1906, 14 



3 ) Liebig's Annalen 350 (1906), 204. 



4 ) Ibidem, 229. 



