[james_a]

Cold, dilute KMnO4 is in every organic chemistry textbook as a dihydroxylation reagent. March says yields rarely exceed 50%. I know of exactly one individual who has used KMnO4 for dihydroxylation, on one occasion. Wondering if it's just me or if this is a set of conditions that is "textbook only"

[movies]

I am pretty sure that it is used industrially because it is such a cheap oxidant.  Certainly not something that would be first on your list, but using massive quantities of osmium is not really an option due to cost and toxicity.

[james_a]

Good point.

[g-bones]

Definitely not your first choice, KMnO4 is very strong and has a low functional group tolerance.  you can use osmium tetroxide stoichiometrically but that isn't very great either.  so in order to make the reaction optimal you can use catalytic osmium tetroxide in the presence of NMO as the stoichiometric oxidant.  hope this helps

[MissPhosgene]

well, if you used it to cleave an olefin you have "used" it for dihydroxylation (if you want to count the olefin-O-Mn complex as a diol)... and then some. Too strong.