Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: JoeyBob on April 03, 2021, 03:18:40 AM
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Im trying to figure out the mechanism for the above and am quite confused. I can find a lot of literature involving lactone formation when a reaction occurs between an alcohol and carboxylic acid group, but have not found anything for a reaction between an alkene and a carboxylic acid group.
I have a mechanism shown here that would give the right product after reacting with a base, but I really doubt that such a reaction would occur, since 2 cations are formed. Intuitively the C=O part of the compound also feels like a better electrophile than the OH, but if this reaction occurred no ester is formed.
The catalysis is amberlyst-15, an acid, but I dont really see how protonation here leads to a lactone. I could see this causing water to leave the compound, but that would give the wrong product.
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You have to much positive charges. In my opinion the H+ from the carboxyl group attack the double bond and on the second carbon there will a positive charge. This charge react with negativ charge on COO- to build the Lacton.
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@chenbeier True, but after addition of H+ positive charge will located on the first, rather than second carbon atom.
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Yes it is the first one (Markovnikov), otherwise the product can not be formed.