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    The substance R has the structural formula : CH3CH2CHOHCOOH
    Draw the structure of the main organic product formed in each case when R reacts separately with the following substances:
    methanol in the presence of a few drops of concentrated sulphuric acid;
    acidified potassium dichromate(VI);
    i'm alot confused on this question so can give me a detailed explanation as to how to work the structure out please?
    Thankyou!
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    (Original post by elvss567)
    The substance R has the structural formula : CH3CH2CHOHCOOH
    Draw the structure of the main organic product formed in each case when R reacts separately with the following substances:
    methanol in the presence of a few drops of concentrated sulphuric acid;
    acidified potassium dichromate(VI);
    i'm alot confused on this question so can give me a detailed explanation as to how to work the structure out please?
    Thankyou!
    I will write down my thought process.

    1.) Methanol is an Alcohol. CH3OH

    Now think about what the important groups in R actually are,

    We have:

    . -COOH, Carboxylic acid group
    . - OH, a hydroxyl group.

    Now which group do you know that will react with Methanol under catalytic H+ (Sulphuric acid)?

    Answer: The carboxylic acid group.

    Im not giving you the structure but Ill tell you that the product will be an ester, done via the fischer esterification. You won't need to derive the mechanism.

    2.) What does acidified K2+ Cr2O72- actually do?

    It oxidises certain oxygen-based functional groups.

    What do you have in R?

    . -COOH, Carboxylic acid group
    . - OH, a hydroxyl group.

    We know now that it won't oxidise the Carboxylic acid group as it's at the highest order of oxidation. So it must be oxidising the Hydroxyl group.

    Again the mechanism is too complex for GCSE/A level, but you should know that a Secondary Alcohol oxidises to a ketone and no further.

    So the product is R but with a Ketone and a Carboxylic acid group.
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    (Original post by _NMcC_)
    I will write down my thought process.

    1.) Methanol is an Alcohol. CH3OH

    Now think about what the important groups in R actually are,

    We have:

    . -COOH, Carboxylic acid group
    . - OH, a hydroxyl group.

    Now which group do you know that will react with Methanol under catalytic H+ (Sulphuric acid)?

    Answer: The carboxylic acid group.

    Im not giving you the structure but Ill tell you that the product will be an ester, done via the fischer esterification. You won't need to derive the mechanism.

    2.) What does acidified K2+ Cr2O72- actually do?

    It oxidises certain oxygen-based functional groups.

    What do you have in R?

    . -COOH, Carboxylic acid group
    . - OH, a hydroxyl group.

    We know now that it won't oxidise the Carboxylic acid group as it's at the highest order of oxidation. So it must be oxidising the Hydroxyl group.

    Again the mechanism is too complex for GCSE/A level, but you should know that a Secondary Alcohol oxidises to a ketone and no further.

    So the product is R but with a Ketone and a Carboxylic acid group.
    That was such a good explanation! I actually understood what was going on.Thankyou!
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    (Original post by elvss567)
    That was such a good explanation! I actually understood what was going on.Thankyou!
    np, good luck
 
 
 
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