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Homework Help: Diel Alder rxn

  1. Mar 14, 2008 #1
    [SOLVED] Diel Alder rxn

    I did a lab on Diels-Alder Reaction of cis-Butadiene with Maleic Anhydride

    I would really apprciate any help on these

    Why do the anhydride substituents of the maleic anhydride reactant help the Diels-Alder reaction, i.e. they help the reaction go faster.

    Why does the diene need to be in the s-cis conformation to give the cyclic product?

    Why is it not possible for the Diels-Alder reaction to make the trans product 4-cyclohexene-trans-1,2-dicarboxylic acid anhydride?

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Mar 14, 2008 #2
    The rate of a Diels-Alder reaction is usually increased if there are electron-donating groups attached to the dienophile and electron-withdrawing groups on the diene. If these criteria are met, the electron density of the diene decreases, making it more electophilic, while the dienophile's electron density increases and it becomes more nucleophilic.

    The diene must be cis because of the required reaction; most textbooks will show the arrow-pushing mechanism for this; it's hard to explain without illustrating.

    Not sure about question 3; it may have to do with the endo rule.
  4. Mar 15, 2008 #3
    Yea thanx for the help. I was able to proceed from there
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