Definition:-

The new Tifeneau-Demjanov system is a chemical reaction in which α-diazoketone is converted to a chain under basic conditions. This new system proceeds through various steps and is named after the physicians who discovered it.


 

1. *Synthesis of diazoketones*: The reaction usually begins with the generation of α-diazoketones, containing a diazo group (N2C=) attached by a ketone group

(R-CO-).

 

2. *Base-catalyzed rearrangements*: α-diazoketones rearrange in the presence of a base, such as triethylamine (NEt3) or potassium tert butoxide (KOtBu) .The base removes a proton from the adjacent carbon, displacing the ketone group go somewhere else.

 

3. *Formation of ketine*: Due to this rearrangement, α-diazoketone is converted to ketine (R'-C=C=O), where the ketine function (C=C=O) is directly related to the adjacent carbon atom .

 

                             

                                          REACTION   MEACHNISM

 

A-




 

 

B-



 

 

 

 

 4. *Applications*: The Tifeneau-Demzanov rearrangement is a valuable method for the synthesis of ketones, which are versatile intermediates in organic synthesis. Ketins can react with nucleophiles such as amines or alcohols to form a variety of reactive compounds.