SYNTHETICAL EESEARCHES ON ACIDS OF THE LACTIC SERIES. 



813 



diethoxalate. The formation of ethylic diethoxalate is explained in the following equa- 

 tions : — 



IC O Eto 



IC O Eto 



Ethylic oxalate. Zincethyl. 



+ 2Zn"Et2 



rCEt2(0Zn"Et) 

 IC O Eto 



Ethylic zincmonethyl 

 diethoxalate. 



+ 



The first of these equations expresses the action of zincethyl upon ethylic oxalate, 

 by which ethylic zincmonethyl diethoxalate is formed*. The second shows the action 

 of water upon this compound, by which the zincmonethyl (Zn C2 H5) becomes replaced 

 by hydrogen f. Although we have not been able to isolate the body ethyUc zincmo- 

 nethyl diethoxalate from the other product of this decomposition, yet we have proved 

 its existence by forming it synthetically, as described below. 



Ethylic diethoxalate is a colourless, transparent, and somewhat oily liquid, possessing 

 a peculiar and penetrating ethereal odour, and a sharp taste. It is insoluble in water, 

 but readily soluble in alcohol or ether. Its specific gravity is '9613 atl8°"7 C ; it boils 

 at 175° C. and distils unchanged. Two determinations of the specific gravity of its 

 vapour gave the following results : — 



I. 



Weight of ethylic diethoxalate -3723 grm. 



Observed volume of vapour . lOO'Ocub. centims. 



Temperature of bath 202° C. 



Difference of heights of mercury inside and out-) ^„ „„ .,,. 

 . , , > o9'00 milhms. 



side tube J 



Heightof oil-column reduced to millims. mercury 19-0 „ 



Height of barometer 763 „ 



Specific gravity of vapour 5'241 



10 01?+ ~ ^ ^^^^' ^^^^^^^s *^^ number 5-528. We hav 



II. 

 •1622 grm. 

 46'17 cub. centims. 

 205° C. 



119 millims. 



17-9 „ 

 775 „ 

 5-23 



The formula C, 



or 



remarked on this and other similar discrepancies below. 



* This interpretation of the reaction was first proposed by Butleeow (Bui. Sec. Chimique, 1864, p. 116) ; and 

 wo have since confirmed it by the synthetical production of ethyUe zincmonethyl diethoxalate, as described 

 below. 



t The final result of this reaction is exactly homologous with the production of glyeollic acid by the action 

 of nascent hydrogen upon oxalic acid, described by Schtjlze (Ann. de Chim. et de Phys. t. Ixvii. p. 366), 



ICOHo + ^^- icOHo + ^^^- 

 Oxalic acid. Glyeollic acid. 



