8.3.4 Beckmann Rearrangement

Oximes rearranges in acidic conditions to give amides. The reaction is intramolecular and stereospecific: the substituent trans to the leaving groups migrates.

An interesting application of this method is the synthesis caprolactam from cyclohexanone oxime. Caprolactam is the substrate precursor for nylon preparation.

 

Mechanism

Examples:

The rearrangement of amidoximes lead to the formation of urea derivatives which is called the Tiemann Rearrangement