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Grignard and Carboxylic acid

Discussion in 'DAT Discussions' started by JustwantDDS, Aug 4, 2011.

  1. JustwantDDS

    JustwantDDS DrAMG
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    What happens here?
    can someone link me something so i can look at it

    i tried searching but couldnt really get what i was looking for
     
  2. toothhornet88

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    http://www.mhhe.com/physsci/chemist...arey04oc/ref/ch19reactioncarboxylicacids.html
    go where it says Preparation of Carboxylic Acid Derivatives and look where it has a carboxylic acid reacting with a base...well that's what happens when grignard reacts with a carboxylic acid. Plus if you have more than one mole of Grignard it will latch on to the O- to become O-MgX
     
  3. Demps

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    I think you get two rounds of nucleophilic attack on the carbnoyl and end up with a tertiary alcohol
     
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  4. Clancyp

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    Usually its the same with esters too.
     
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  5. needzmoar

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    The grignard and a carboxylic acid is a wasteful acid base reaction. I believe you and the posters above are looking for the organolithium reagent with a carboxylic acid followed by hydrolysis to form a ketone. That's one of the key differences between organolithium reagent vs the grignard.

    edit: here's a link http://www.orgsyn.org/orgsyn/prep.asp?prep=cv5p0775

    essentially it's just 2 molar eq of RLi + carboxylic acid followed by acidic hydrolysis
     
    #5 needzmoar, Aug 5, 2011
    Last edited: Aug 5, 2011
  6. PooyaH

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    That would be the case with esters, which is called sapofinication (ester hydrolysis by a strong base), but Gringard always reacts with the most acidic hydrogen first. So in case of carboxylic acid, it would make a carboxylate.
     

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