Oxydation of cyclic enol with KMnO4

[duchuy]

Homework Statement

Please help me find the mechanism

Relevant Equations

x

Hi, please help me write the mechanism of this reaction. Usually id have an alpha hydrogen for me to do an internal proton transfer, but in this case i don't know what to do. I know the last step is wrong but i don't know how to obtain a carbonyl orcarboxylic acid form this.
Thank you so much for your help!

 

[TeethWhitener]

Caveat: practically speaking, KMnO₄ is quite a strong, non-specific oxidizer, so in real life there’d likely be a mix of products.

That said, I’d focus on the ene side of the enol before the hydroxyl side. KMnO₄ operates like periodates when it comes to double bonds.

 

[duchuy]

Caveat: practically speaking, KMnO₄ is quite a strong, non-specific oxidizer, so in real life there’d likely be a mix of products.

That said, I’d focus on the ene side of the enol before the hydroxyl side. KMnO₄ operates like periodates when it comes to double bonds.

Thank you for your answer but I am not quite sure i'd know how to write the mechanism if i start with the ene side. Do i still form a ring of 4 or when i break the pi bond, it would go to the more electronegative oxygen?

 

[TeethWhitener]

I can’t quite parse your response, but one of the key steps of permanganate reacting with alkenes is the formation of a 5-member ring containing the manganese.

 

[chemisttree]

Caveat: practically speaking, KMnO₄ is quite a strong, non-specific oxidizer, so in real life there’d likely be a mix of products.

That said, I’d focus on the ene side of the enol before the hydroxyl side. KMnO₄ operates like periodates when it comes to double bonds.

Yes, true. I believe the conditions should be cold dilute to make the expected product.