What are the products when but-2-enoic acid reacts with aqueous #"KMnO"_4#?
It depends on the conditions.
Reaction with cold, dilute, basic
The reaction forms 2,3-dihydroxybutenoic acid and a dark brown precipitate of manganese dioxide.
The disappearance of the purple colour with the formation of a dark brown precipitate is often used as a test for the presence of
Reaction with hot, acidic
1,2-Diols are easily oxidized by hot, acidic
In hot, acidic solution, but-2-enoic acid is oxidized to acetic acid and oxalic acid.