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    Not sure if I have got 2a but anyway need help with 2c.
    Im not sure what mechanism is it. I tried nuc addition but i dont think thats right.

    Cheers.
    http://m.imgur.com/r7epDqE,QB0r94T,ouaR6K8
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    my chemistry knowledge is rusty so sorry if im wrong

    I pretty sure nucleophilic addition is correct, I've just done the mechanism and it matches yours so, just remember to put the partial charges on the relevant atoms.
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    (Original post by The Diplomat.)
    my chemistry knowledge is rusty so sorry if im wrong

    I pretty sure nucleophilic addition is correct, I've just done the mechanism and it matches yours so, just remember to put the partial charges on the relevant atoms.
    But doesn't match the formula they have given in the question, I don't think? There is a carboxylic acid group?
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    (Original post by Super199)
    Not sure if I have got 2a but anyway need help with 2c.
    Im not sure what mechanism is it. I tried nuc addition but i dont think thats right.

    Cheers.
    http://m.imgur.com/r7epDqE,QB0r94T,ouaR6K8
    do you need help with this?
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    (Original post by Super199)
    But doesn't match the formula they have given in the question, I don't think? There is a carboxylic acid group?
    damn you're right
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    it is nucleophilic addition
    http://www.chemguide.co.uk/mechanism...dd/reduce.html

    right?
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    (Original post by The Diplomat.)
    damn your right
    you're
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    (Original post by z33)
    it is nucleophilic addition
    http://www.chemguide.co.uk/mechanism...dd/reduce.html

    right?
    Yeah I think so but I am messing up the mechanism..
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    the C=O double bond in the COOH group is attacked in acetoacetic acid
    but only one of them is, the other COOH is left alone
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    You've 'attacked' the wrong C=O group. You need to do it to the one that is bonded to the methyl group. It reduces the ketone to a secondary alcohol, giving the CH3CH(OH)CH2COOH that the question asks for.
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    Name:  mechanism.jpg
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    is this right?
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    (Original post by z33)
    Name:  mechanism.jpg
Views: 70
Size:  55.3 KB

    is this right?
    **** i attacked the wrong group x'D
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    fixed

    Name:  mechanism.jpg
Views: 66
Size:  57.3 KB
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    2c is Nucleophilic addition.

    The - will attack the carbocation, provoking the double bond to the O to "Jump up" onto the O giving it a negative charge as well as a lone pair, the lone pair will then donate to a H+ from the NaBH4 to form a secondary alcohol (3-hydoxybutanoic acid).
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    (Original post by z33)
    fixed

    Name:  mechanism.jpg
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    (Original post by GetOverHere)
    You've 'attacked' the wrong C=O group. You need to do it to the one that is bonded to the methyl group. It reduces the ketone to a secondary alcohol, giving the CH3CH(OH)CH2COOH that the question asks for.
    What am I doing wrong now?
    http://m.imgur.com/IhOI6vL
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    (Original post by Super199)
    What am I doing wrong now?
    http://m.imgur.com/IhOI6vL
    you forgot the OH
    everything else is fine
    check my mechanism against yours
    look at the molecule in the question and the molecule you drew

    (Original post by z33)
    fixed

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    (Original post by z33)
    you forgot the OH
    everything else is fine
    check my mechanism against yours
    look at the molecule in the question and the molecule you drew
    Ah cheers.

    Do you mind helping me with another question. How do you work out the number of structural isomers?
    For example the question asks how many different structure isomere could be formed from the mononitration of 1,3,5-trimethylbenzene?

    Thanks
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    (Original post by Super199)
    Ah cheers.

    Do you mind helping me with another question. How do you work out the number of structural isomers?
    For example the question asks how many different structure isomere could be formed from the mononitration of 1,3,5-trimethylbenzene?

    Thanks
    Well there's no formula to work out the structural isomers
    you just have to draw the molecule out and try to find the different combinations

    check out this post
    http://www.thestudentroom.co.uk/show...6&postcount=11 for more detail
 
 
 
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