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Esterification

  • Page ID
    821
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    The π bond of the carbonyl group can act as a base to a strong inorganic acid due to the distortion of the electrons from the electronegativity difference between the oxygen atom and the carbon atom and also the resonance dipole. The cation produced in the reaction with sulfuric acid will have resonance stabilization.

    esterf2.gif

    Mechanism for Acid Catalyzed Esterification

    Step 1: Formation of cation

    esterfication1.gif

    Step 2: The methanol can act as a nucleophile to a carbocation. Remember that there are many methanol molecules in the solution...it is always in excess in this reaction.

    esterfication2.gif

    Step 3: The protonated ether can leave as methanol but that will not accomplish anything. A proton can be transferred to one of the hydroxyl groups and thus make it a good leaving group.

    esterfication3.gif

    Step 4: The alcohol oxygen atom from the hydroxy group can donate a pair of electrons to the carbon atom making a π bond and eliminating water. The water will not be a viable nucleophile that will reverse the reaction because its concentration will be low compared to the concentration of the methanol.

    esterfication4.gif

    Step 5: The water will be in too low a concentration to reverse the reaction.

    esterfication5.gif

    Video of Mechanism

    esterfication.gif


    Esterification is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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