reaction between dicyclopentadiene and maleic acid?

Discussion in 'Chemistry' started by zahraesmaeeli, Jan 23, 2016.

  1. zahraesmaeeli Registered Member

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    I saw in books that reaction between dicyclopentadiene and maleic acid result in dicyclopentadiene-maleat ester. And they said this is and ene reaction but i couldnt understand how this reaction is subset of ene reaction and how ester group is made. because based on ene reaction we will have one carbon with two hydroxy group. how this result in ester group?
    Thanks if you could help me.
     
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  3. exchemist Valued Senior Member

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    My organic chemistry is very rusty but I found a patent reference on the web, :
    http://www.google.com/patents/US6384151

    suggesting that the O of the hydroxy group of one of maleic acid's 2 carboxylic acid groups can saturate one of the double bonds in dicyclopentadiene, resulting in an ester link. Like you perhaps I am a bit puzzled as this seems to involve a net loss of H- from other end of the double bond with both bonding electrons, i.e. as hydride. I would have thought this implies an oxidative step of some sort.......unless there is a hydride shift going on somehow. This system does in fact look close to the famous "norbornyl cation", which as I recall does undergo hydride shifts. But I am too rusty on this to be able to work it out, I'm afraid.

    Perhaps a more up to date chemist can comment........
     
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  5. timojin Valued Senior Member

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    Would you accept if the maleic acid is heated to about 150C were it decompose into maleic anhydride and then you would have an ene reaction with dicyclopentadiene
     
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  7. exchemist Valued Senior Member

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    You might, but surely that would not give a maleate ester as a reaction product, would it? I think that's the point the poster is raising.
     
  8. timojin Valued Senior Member

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    Did they provide the temperature at which they were cooking and the condition ?
     
  9. zahraesmaeeli Registered Member

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    Thanks for your attention.
    Yes they said this reaction is performed at 110-120 degree celsius.
    Because before 110 this reaction doesn't take palce and beyond 120 cyclopentadiene is formed from dicyclopentadien that is not desired.
     
  10. zahraesmaeeli Registered Member

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  11. zahraesmaeeli Registered Member

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    Thanks for your attention.
     
  12. timojin Valued Senior Member

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    I would suspect at about 110 C maleic anhydride will start to form and I assume at about 110 or so the start to add dicyclopentadiene the ene reaction will take place.
     

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