The Hofmann elimination allows the conversion of amines to alkenes. It is a regioselective reaction that follows Hofmann's rule, forming the least substituted alkene.
![hofmann-elimination eliminacion-hofmann](/images/stories/organica-ii/aminas/eliminacion-hofmann/eliminacion-hofmann-01.png)
Stage 1. Exhaustive methylation of the amine. In this step the amine is reacted with excess methyl iodide, to form an ammonium salt (good leaving group).
![hofmann-elimination eliminacion-hofmann](/images/stories/organica-ii/aminas/eliminacion-hofmann/eliminacion-hofmann-02.png)
Stage 2. Treatment with aqueous silver oxide. Basic salt that forms an ammonium hydroxide, precipitating the iodide in the form of silver iodide.
![hofmann-elimination eliminacion-hofmann](/images/stories/organica-ii/aminas/eliminacion-hofmann/eliminacion-hofmann-03.png)
Step 3. Bimolecular elimination. Ammonium hydroxide undergoes an E2 on heating, which gives rise to the alkene.
![hofmann-elimination eliminacion-hofmann](/images/stories/organica-ii/aminas/eliminacion-hofmann/eliminacion-hofmann-04.png)
Being an E2, the Hofmann deletion has ANTI stereochemistry.