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    On Edexcel A2 textbook p.121, there's one SC question I cannot find the answer. It goes "See if you can find out how the process shown in fig.1.6.56 differs when the reaction is carried out using a tertiary alcohol - and why."

    The process shown is about using radioactive isotope of oxygen-18 to find out where the bridging oxygen in ester comes from - alcohol or carboxylic acid. So they mix the the "labelled" ethanol (with oxygen-18), propanoic acid with concentrated sulfuric acid catalyst for esterification.

    I'm thinking the reason why the process would differ when we use tertiary alcohol instead is that it is prone to elimination reaction as conc sulfuric acid catalyst is present. So how can we prevent elimination reaction from predominating esterification??

    So my exact question is: HOW CAN WE MAKE ESTER FROM TERTIARY ALCOHOL??

    If anyone knows the answer, please please explain it to me THANKS A LOT!!!
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    (Original post by mystreet091234)
    On Edexcel A2 textbook p.121, there's one SC question I cannot find the answer. It goes "See if you can find out how the process shown in fig.1.6.56 differs when the reaction is carried out using a tertiary alcohol - and why."

    The process shown is about using radioactive isotope of oxygen-18 to find out where the bridging oxygen in ester comes from - alcohol or carboxylic acid. So they mix the the "labelled" ethanol (with oxygen-18), propanoic acid with concentrated sulfuric acid catalyst for esterification.

    I'm thinking the reason why the process would differ when we use tertiary alcohol instead is that it is prone to elimination reaction as conc sulfuric acid catalyst is present. So how can we prevent elimination reaction from predominating esterification??

    So my exact question is: HOW CAN WE MAKE ESTER FROM TERTIARY ALCOHOL??

    If anyone knows the answer, please please explain it to me THANKS A LOT!!!
    Tertiary alcohols tend to lose their hydroxyl groups forming a carbocation. This would mean that the carboxylic acid is reacting with a carbocation so that the oxygen will always come from the carboxylic acid.

    TLDR: The mechanism of esterification is different for tertiary alcohols.
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    (Original post by charco)
    Tertiary alcohols tend to lose their hydroxyl groups forming a carbocation. This would mean that the carboxylic acid is reacting with a carbocation so that the oxygen will always come from the carboxylic acid.

    TLDR: The mechanism of esterification is different for tertiary alcohols.
    So for esters produced from primary or secondary alcohols, the oxygen atom comes from alcohol, while for those produced from tertiary alcohols, it comes from acid?
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    (Original post by mystreet091234)
    So for esters produced from primary or secondary alcohols, the oxygen atom comes from alcohol, while for those produced from tertiary alcohols, it comes from acid?
    I don't know for certain, but it seems to be a reasonable assumption. I don't have any organic texts with me at the moment so I can't check.
 
 
 
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