[Hubert]

how oxidation work in hydrocarbon in the presence of KMnO4. For e.g this.
cyclohexene + KMnO4 = cis-1,2-cyclohenanediol


i tot oxidation onli works when it removes one hydrogen atom from a hydroxyl grp attached to the carbon and another hydrogen attached to the same carbon...so how does this work from this equation i wrote above

[FeLiXe]

cis means they are both on the same side

you go through a cyclic ester

you end up with Mn(V) in MnO₃^- (which will disproportionate and react again)

[Arsenic]

[Mitch]

Hubert: Spell check your posts and write better topic subjects or be banned. Review forum policy on how to write subjects titled "Read This Before Posting!"

[Hubert]

hey...ok...now this is the part...oh...where did the hydrogen come from....how cum it attaches to the oxgen atom form nowhere

[Hubert]

and to what i learn in class...oxidation only involve the lose of a hydrogen attached to the carbon and a hydrogen of a hydroxyl grp attached to the same carbon...then how did oxidation work in the above diagram...sorrie...i'm realli confused

[Arsenic]

see if this sheds any light on things

[Hubert]

i mean with only cyclohexene and pottaium permanganate...how do they oxidise to becum an alcohol?

[Albert]

To quote the poet, 'Water,water, water, nor any drop to drink!'

Water plays its role in this reaction by 'giving' H-atoms to the diol. Arsenic posted a complete mechanism for this reaction, where you can appreciate how water 'completes' the diol.
Not only does water take part in the reaction: also OH- does it!

However, if you want to see the electrons moving, look at the arrows (every arrow is a couple of electrons)