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11.3: Alkenes as Weak Bases, Outcomes of Protonation at Pi Bonds

  • Page ID
    215881
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    As stated before, the double bond in alkenes is a source of electrons. Alkenes are weak bases because the π-electrons are only available after breaking the π-bond first. Nonetheless, alkenes are capable of becoming protonated by strong acids. The most important principle to keep in mind is that with unsymmetrical alkenes, formation of the most stable carbocation is the preferred outcome.

    clipboard_ebb59836bca97e1488cad67c23f393eb3.png

    Protonation of the unsymmetrical alkene favors formation of the most stable carbocation. In this example the tertiary cation is favored over the secondary one.

    clipboard_e9f935cc8ff8febd1d6fd1c39356a9f34.png

    Can you show the electron movement taking place here and the exact location of the new C-H bond in the carbocation that forms?


    This page titled 11.3: Alkenes as Weak Bases, Outcomes of Protonation at Pi Bonds is shared under a not declared license and was authored, remixed, and/or curated by Sergio Cortes.

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