https://www.thevespiary.org/rhodium/Rhodium/chemistry/benzaldehydes.kmno4.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/benzaldehydes.kmno4.html)
it states here that to oxidise styrene to benzaldehyde, 4.65g of KMnO4/alumina reagent is required to oxidise 1mmol! that seems entirely rediculous! if one wanted to oxidise 100mmol, which is only about 5 grams, one would require over a pound of KMnO4/alumina reagent plus enough DCM to dissolve everything! why is so much reagent required to reduce so little? this seems entirely impractical if one wanted straight benzaldehyde...
the alternative low yielding aqueous permanganate oxidation doesn't
look tasty either: https://www.thevespiary.org/rhodium/Rhodium/chemistry/tma2np.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/tma2np.html)
seems like permanganate oxidations simply do suck.
> i was wondering, since toluene can bee chlorinated to benzal chloride
> then reacted with either ZnCl or CaCO3 + H2O to form benzaldehyde, could
> styrene also bee chlorinated in the same fashion then reacted similarly to
> form benzaldehyde, just like a toluene substitute? (since they form the same
> compound when reacted with mnO2 + H2SO4)
no. chlorine would add accross the double bond giving an unwanted compound.
(something like 1,2-dichloro-1-phenyl-ethane)
but tell: you can get styrene and not toluene!?