Chemistry Forums for Students > Organic Chemistry Forum
Mechanism for lactone formation from 3-noneoic acid.
(1/1)
JoeyBob:
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.
chenbeier:
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.
Orcio_87:
@chenbeier True, but after addition of H+ positive charge will located on the first, rather than second carbon atom.
chenbeier:
Yes it is the first one (Markovnikov), otherwise the product can not be formed.
Navigation
[0] Message Index
Go to full version