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    (Original post by moomooo)
    I put the same except NaBH4 to reduce the COOH group
    YAAAY. You could use either LiAL4 or NaBH4 they both essentially do the same thing. I *think* we done the last page okay then:yep:
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    Erm … wouldn't NaBH4 reduce the carbonyl which is present in both compunds, I know one was an peptide bond, but … I was thinking of using those, but thought it would be a little risky.
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    (Original post by Emmalouise1990)
    Was H20 the reagent for A? I think that's what I put.
    That's what I put as well, it's definitely correct, but it's possible it won't be awarded on the mark-scheme due to it forming two organic products.
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    Went well but just remembered I didnt go back to mechanism question! :O Oh no!!! That was a easy one too! Ah well...also last section not too nice!
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    (Original post by TwilightKnight)
    Erm … wouldn't NaBH4 reduce the carbonyl which is present in both compunds, I know one was an peptide bond, but … I was thinking of using those, but thought it would be a little risky.
    No, because one was an ester link and the other a peptide bond. NaBH4 and K2Cr2O7/H2SO4 doesn't effect them.
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    (Original post by Noble.)
    That's what I put as well, it's definitely correct, but it's possible it won't be awarded on the mark-scheme due to it forming two organic products.
    I drew both organic products too, so I probably lost the mark.
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    (Original post by Emmalouise1990)
    I drew both organic products too, so I probably lost the mark.
    So did I. There's a past paper where the question just stated "product", but there were in fact two products, I'm looking for it now. To be honest, it'd be quite stupid if they won't award marks for the hydrolysis of them, considering it is the main reaction in common to a peptide bond and an ester link.
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    (Original post by TwilightKnight)
    Erm … wouldn't NaBH4 reduce the carbonyl which is present in both compunds, I know one was an peptide bond, but … I was thinking of using those, but thought it would be a little risky.

    Nope, it only reduces the carboxylic acid group. I don't know how they expected to know that, though, luckily I made a synthesis diagram using the old spec textbooks and that reaction was in there
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    Actually meant to write LiAl4. Got NaBH4 on the brain. We learnt in S&C that LiAl4 reduces esters, which is why I tried to avoid using a lit of S&C knowledge on that paper, as a lot of it goes beyond the scope of the course without you knowing.
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    (Original post by FoOtYdUdE)
    i think it was summat like (CH3)2CHCOOCH3 :o:
    freak yeah , it was the best we could have gotten. But as usual i managed to screw things up by running out of time.
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    (Original post by Mr van der WAALs)
    For the last question I put:
    Reagent A: NaOH produce salt of carboxylate and phenolic salt
    Reagent B: KOH - reactive metal reacts with COOH functional group in asprin
    Reagent C: Br2 again - only reaction i could think of with phenol at the time :|
    my answers were:
    A = Na
    B= Na2CO3
    C = Br2

    edit: I confused the wrong question my bad
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    (Original post by Noble.)
    So did I. There's a past paper where the question just stated "product", but there were in fact two products, I'm looking for it now. To be honest, it'd be quite stupid if they won't award marks for the hydrolysis of them, considering it is the main reaction in common to a peptide bond and an ester link.
    harvest you porn star!! whatya get for reagents A, B and C?
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    I mucked up the NMR question so BAD. I got the right structure (somehow) but my reasoning failed, as I thought it was a quadruplet peak
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    (Original post by Emmalouise1990)
    Was H20 the reagent for A? I think that's what I put.

    You could put Dil HCL or NAOH(aq).

    Or any acid/alkaline if you put dil/(aq) in as well i think.
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    Also, preeetty sure NaBH4 doesn't reduce -COOH. LiAlH4 does though.
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    (Original post by TwilightKnight)
    Also, preeetty sure NaBH4 doesn't reduce -COOH. LiAlH4 does though.
    NaBH4 does reduce -COOH. All NaBH4 and LiAlH4 do is provide H- ions.
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    The question about acid anyhidride.
    We were given 3 reactions right, I had so little time that I didn't really at them.
    I managed to answer the question, but for the questions did we have to refer to any of the reactions.
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    (Original post by _Andrew_)
    I mucked up the NMR question so BAD. I got the right structure (somehow) but my reasoning failed, as I thought it was a quadruplet peak
    which one was the right structure? i managed to get that CH3 was a singlet, and there was a CH somewhere, and a COOC in the middle, with CH3 at the end possibly?
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    (Original post by Noble.)
    So did I. There's a past paper where the question just stated "product", but there were in fact two products, I'm looking for it now. To be honest, it'd be quite stupid if they won't award marks for the hydrolysis of them, considering it is the main reaction in common to a peptide bond and an ester link.
    I hope they do.We techniqually got the question right...it was a vague question, so they are a number of possible answers that could be correct!
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    (Original post by Pedus)
    which one was the right structure? i managed to get that CH3 was a singlet, and there was a CH somewhere, and a COOC in the middle, with CH3 at the end possibly?
    I got (CH3)2CHCOOCH3.
 
 
 
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