Leucic acid i ^ ^ tt 



ICO Ho 



SYNTHETICAL EESEAECHES ON ACIDS OF THE LACTIC SERIES. 355 



The properties of acetonic acid and its salts, as described by Staedeler, agree well with 

 those which we have observed in dimeth oxalic acid and its compounds : both acids evolve 

 an odour of acetone on being heated with potassic hydrate, and are decomposed without 

 blackening by concentrated sulphuric acid, with evolution of much gas. 



The third of the above formulae is obviously that of Heintz's ethyl-glycoUic acid*. 

 The origin of WuRTz's butylactic acid, which was prepared by an analytical process, does 

 not permit of any safe conclusion being drawn as to its constitution. 



Of the possible acids containing five atoms of carbon, only one (the ethomethoxalic 

 acid described above) is known f. 



Of acids containing six atoms of carbon three are known, to which we assign the 

 following formulae : — 



rCBuHHo 



l( 



w , ,• ., fCEtaHo 



Uiethoxahc acid •{ /- ,^ tt 



|,C O Ho 



rCH.Ho 



Paraleucic acid < C4 Hg 



[CO Ho 

 The above formula for leucic acid is founded upon Limpbicht's J interesting reaction for 

 the synthetical production of this acid from valerianic aldehyde and hydrocyanic acid. 

 KoLBE has shown that valerianic acid contains butyl ; consequently valeraldehyde has 



the constitution expressed by the formula ] p ^ tt , and Limpricht's reaction may there- 

 fore be explained by the following equation, 



Ammonic Leucin. 



valeraldehyde. 



Such being the rational formula of leucin, its transformation into leucic acid by nitrous 

 acid determines the constitution of leucic acid, 



rCBuH(NH,) ,„^,jj__^fCBuHHo 



ICOHo ICOHo ^ ^ 



Leucin. Nitrous acid. Leucic acid. 



We entertain no doubt of the isomerism of leucic and diethoxalic acids, although we 

 have not yet been able to observe any substantial difierence between them ; both acids 



* Pogg. Ann. cix. 331. 



t Yalerolactic acid, ( | p --> tt )' J"^* discovered by Fittig, forms a second. Its isomerism with ethometh- 

 oxalic acid is proved by its melting-point, which is 80° C, whilst ethomethoxalic acid fuses at 63° C— April 

 29, 1866. 



t Ann. der Ch. und Pharm. Bd. xciv. S. 243. 



