Dihydroxylation of Alkenes Os

Osmylation occurs much more rapidly in the presence of amines than it does in their absence. The addition of a chiral amine like an 0-alkyl- or O-aryldihy-droquinine or -quinidine to a mixture of OSO4 and an alkene allows asymmetric dihydroxylation of prochiral alkenes. The chiral amine-0s04 complex adds preferentially to one face of the alkene over the other. 

KMn04 can also accomplish dihydroxylation of alkenes, particularly electron-poor ones. It can oxidize more electron-rich alkenes further to the dicarbonyl compound. It can also oxidize alkanes, especially alkylbenzenes to the arylcar-boxylic acids. The mechanisms of these reactions remain quite obscure. 

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