Solution Found!
Propose a mechanism for the following ring-opening
Chapter 15, Problem 14P(choose chapter or problem)
Propose a mechanism for the following ring-opening transesterification. Use the mechanism in Problem 21-13 as a model.
\(\mathrm{CH}_{3} \mathrm{OH}\)
\(\mathrm{OCH}_{3}\)
Equation transcription:
Text transcription:
{CH}{3}{OH}
{OCH}{3}
Questions & Answers
QUESTION:
Propose a mechanism for the following ring-opening transesterification. Use the mechanism in Problem 21-13 as a model.
\(\mathrm{CH}_{3} \mathrm{OH}\)
\(\mathrm{OCH}_{3}\)
Equation transcription:
Text transcription:
{CH}{3}{OH}
{OCH}{3}
ANSWER:Solution:
Here we have to propose a mechanism for the following ring-opening transesterification reaction:-
Step 1
Tetrahydropyran-4-one on reaction with methyl alcohol in acid medium form methyl-4-hydroxybutanoate as the product.
(Tetrahydropyran-4-one) (Methanol) (methyl-4-hydroxybutanoate)
Mechanism:
In this mechanism tetrahydropyran-4-one undergoes protonation in presence of an acid and forms an intermediate (3-resonance structures), the most stable intermediate (carbocation) will react with CH3-OH (substitution reaction) and form 2-methoxy-2-hydroxytetrahydropyran, which in presence of an acid again undergoes
protonation and the cleavage of C-O has been carried out with the formation of methyl-4-hydroxybutanoate as the final product.
