88 PRACTICAL ORGANIC AND BIO-CHEMISTRY 



KETONES. 



Ketones are the first products of the oxidation of secondary 

 alcohols, e.g. : 



CH 3 CH 3 CH 3 



I I / OH I 



CHOH ->C< -> CO 



I XOH I 



CH 3 CH 3 CH 3 



Isopropyl alcohol. Hypothetical. Acetone. 



The same statements apply here as in the case of the formation of 

 aldehydes. 



The group >CO is characteristic of ketones. 



Acetone is the first member of the homologous series of ketones 

 and the chief representative. 



ACETONE. 



Preparation. 



Acetone is formed in the dry distillation of wood and is separated 

 from methyl alcohol by fractional distillation (p. 63). 



Acetone is also prepared by the dry distillation of calcium or 

 barium acetate : 



CH 3 . COO. CH 3 v 



>Ca = )CO + CaC0 3 . 



CH 3 . COO/ CH 3 / 



50-100 gm. of dry calcium acetate are placed in a retort or dis- 

 tilling flask and at first heated gently, afterwards more strongly, and 

 the vapours are passed through a condenser. A brownish liquid col- 

 lects in the receiver. It contains acetone, aldehyde and higher ketones. 

 The acetone is separated by fractional distillation. 



