44 ORGANIC AGRICULTURAL CHEMISTRY 



This will be referred to again when we discuss photo-synthesis 



(p. 239)- 



Acetaldehyde 



Ethyl alcohol similarly oxidized yields acetic aldehyde or 



acetaldehyde. 



/H /H 



CHs-C^H +0->CH3-C=0 + H20 

 \0H 



Ethyl alcohol Acetaldehyde 



These two aldehydes are known as formic and acetic aldehydes 

 because, on further oxidation, with the taking up of oxygen, they 

 y\Q\d formic acid and acetic acid respectively. 



Aldehyde Reactions 



Addition Compounds. — Some of the reactions of aldehydes 

 are important and should be mentioned, as they will be referred 

 to later. When acetaldehyde is treated with ammonia or with 

 hydrogen cyanide, addition products are formed probably as 

 follows : 



CH3 - C^ O + NH3 -^ CH3 - C^OH 



\NH2 



Acetaldehyde Aldehyde ammonia 



/H /H 



CH3- C^O + HCN -^ CH3- C^OH 



Acetaldehyde Aldehyde hydrogen cyanide 



Oximes. — When aldehydes are treated with hydroxyl amine 

 (hydroxyl ammonia) , H2N — OH, the two amine hydrogens of 

 the latter compound unite with the oxygen of the aldehyde, 

 forming water, the following reaction taking place : 



/H /H 



CH3- C= (O + H2)N- OH ^ CH3- C = N- OH + H2O 



Aldehyde Hydroxyl amine Ald-oxime 



The product is known as an oxime. 



