Arndt Eistert Reaction
Arndt-Eistert reaction convert a carboxylic acid to a higher homologue with one additional carbon atom.
The following steps are involved in the Arndt-Eistert reaction-
1. Conversion of carboxylic acid to an active compound like acid chloride or an anhydride.
2. Conversion of acid chloride to a diazoketone.
3. Diazoketone is rearranged to ketene (Wolf Rearrangement) by heating with Ag2O in the presence of water.
4. Ketene is then reacts with water to form higher homologue with one additional carbon atom.
Excess of diazomethane is used to consume the liberated HCl. In the absence of excess diazomethane, diazoketone is lost in reacting with HCl to form chloromethyl ketone.
If alcohol, ammonia or amines are used in place of water in the last step then ester, amide or substituted amide respectively formed.
The following steps are involved in the Arndt-Eistert reaction-
1. Conversion of carboxylic acid to an active compound like acid chloride or an anhydride.
2. Conversion of acid chloride to a diazoketone.
3. Diazoketone is rearranged to ketene (Wolf Rearrangement) by heating with Ag2O in the presence of water.
4. Ketene is then reacts with water to form higher homologue with one additional carbon atom.
Excess of diazomethane is used to consume the liberated HCl. In the absence of excess diazomethane, diazoketone is lost in reacting with HCl to form chloromethyl ketone.
If alcohol, ammonia or amines are used in place of water in the last step then ester, amide or substituted amide respectively formed.