 Asymmetric dihydroxylation

Asymmetric dihydroxylation adds two hydroxyl groups across an alkene while favouring one stereochemical product. In the Sharpless approach, a chiral ligand controls an osmium-based catalytic environment, turning an otherwise face-symmetric reaction into an enantioselective transformation.^[ref]

The new oxygen-bearing centres are formed in a correlated addition. Substrate geometry and the ligand's handedness jointly determine which stereoisomer is favoured.