KMnO4 (hot) oxidation versus cleavage

[fayevalentine]

I am extremely confused and hoping someone might be able to help me figure this one out. Considering the two reactions below:

In the first reaction, the hot KMnO4 only oxidizes the methyl group. Why doesn't it cleave the double bonds in the ring? It cleaves the ring's double bond in the second reaction, so why not in this first?


REACTION 1:

REACTION 2:

I have a feeling I'm missing something very silly, but this has me stumped.

Thank you so much for any responses!!

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[Mad Jack]

All I saw was hot and cleavage. Sorry I can't help.

 

[FeralisExtremum]

First ring is aromatic, second one isn't (the second one also has no H's on the benzyl carbon). The first reaction is a specific one, the permanganate oxidation affects benzyl carbons. The second molecule has no benzene ring, so that reaction shouldn't even be a consideration.

As for the why, that's way beyond my depth. I assume it has to do with benzenes being stable structures and thus less reactive.

 

[fayevalentine]

First ring is aromatic, second one isn't (the second one also has no H's on the benzyl carbon). The first reaction is a specific one, the permanganate oxidation affects benzyl carbons. The second molecule has no benzene ring, so that reaction shouldn't even be a consideration.

As for the why, that's way beyond my depth. I assume it has to do with benzenes being stable structures and thus less reactive.

Thank you so much!!! That makes a ton of sense. Now I won't be up all night trying to figure this out lol!