PROBLEM 25.26 - Organic Chemistry

Question

Question: Draw the product formed by treating each compound with excess CH₃I , followed by Ag₂O , and then heat.

a.

b.

c.

Step-by-Step Solution

Answer

Answer 

a.CH₃CH₂CH$=$CH₂

b.CH₃CH$=$CH₂

c.

Hoffmann elimination

Hoffmann elimination forms alkene from the amine. It is completed in three steps:

• In the first step, the quaternary ammonium salt is formed by the reaction of amine with the excess of alkyl halide via S_N2  reaction. 
• The second step involves the conversion of one ammonium salt into another with a different anion. The silver (I) oxide Ag₂  replaces the iodide anion with the hydroxide ion. 
• In the third step, hydroxide ion (base) removes a proton from the alpha carbon atom when the ammonium salt is heated, forming the alkene.

 

Explanation

a. The reaction of the given amine is completed via the Hoffmann elimination process as:

b. The given amine produces the product alkene via the Hoffmann elimination process as:

c. The given amine produces the product alkene via the Hoffmann elimination process as:

Hoffmann elimination