Dihydroxylation reaction of alkene.
To convert alkenes into cis-diols by syn dihydroxylation, they are reacted with a basic solution of potassium permanganate (KMnO4) or Osmium tetroxide (OsO4). Both reactions go through the formation of a cyclic intermediate which is formed by a syn addition to the double bond. The intermediates are then hydrolyzed by water during which the stereochemistry of newly-formed C-O bonds is retained thus producing cis-diols.
