Q33E - Organic Chemistry (Mcmurry)

Question

Reaction of 2-methylpropene with CH₃OH in the presence of H₂SO₄

catalyst yields methyl tert-butyl ether, CH₃OC(CH₃)₃, by a mechanism

analogous to that of acid-catalyzed alkene hydration. Write the mechanism,

using curved arrows for each step.

Step-by-Step Solution

Answer

Mechanism of the reaction is:

Step 1: Acid- Catalyzed alkene hydration

Hydration reactions are those reactions in which water molecules are added on any compound such as alkenes. In water molecules hydrogen bonding is present and hydrogen bonding is the strongest bonding therefore, no reaction will take place if we will simply do the reaction of alkene with water. For this type of conditions we generally use an acid such as \({{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}\) to perform our hydration reaction with alkenes.

Step 2: Formation of methyl-tert-butyl ether

Step 3: Mechanism

Mechanism of this reaction is as follows:

Step 1: Addition of electrophile (\({{\bf{H}}^{\bf{ + }}}\)) on the double bonds of alkene.

Step 2: Lone pairs of oxygen atom i.e. nucleophile will attack on the tertiary carbocation.

Step 3: In the last step proton will be released and we will get our product.

                                                   Mechanism of the reaction