What does #OsO_4#/ #tBuOOH#/#HO^-#or #KMnO_4#/#NaOH#/0°C do?

1 Answer
Jan 3, 2015

Both reactants convert alkenes to vic-diols.

#"OsO"_4"/t-BuOOH/HO"^(-)"Reaction:"#

www.chem.ucalgary.ca

  1. The OsO₄ is a catalyst. It reacts with the π electrons of the alkene in a syn addition to form a cyclic osmate ester.

  2. The OH⁻ hydrolyzes the ester. This forms the cis-diol and H₂OsO₄.

  3. The t-BuOOH oxidizes the H₂OsO₄ and regenerates the OsO₄ catalyst: t-BuOOH + H₂OsO₄ → t-BuOH + OsO₄ + H₂O


**#"KMnO"_4"/NaOH/0°C Reaction:"#

www.chemgapedia.de

As with OsO₄, the reaction goes through a cyclic ester to form a cis diol.

In this case, the MnO₄⁻ is a reactant, not a catalyst, because the MnO₄⁻ is not regenerated.