Home > Organic Chemistry > Osmylation-OsO4 (Osmium Tetroxide)

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

Answer 1

Ava Andrews

Both reactants convert alkenes to vic-diols.

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

The OsO₄ is a catalyst. It reacts with the π electrons of the alkene in a syn addition to form a cyclic osmate ester.
The OH⁻ hydrolyzes the ester. This forms the cis-diol and H₂OsO₄.
The t-BuOOH oxidizes the H₂OsO₄ and regenerates the OsO₄ catalyst: t-BuOOH + H₂OsO₄ → t-BuOH + OsO₄ + H₂O

**#"KMnO"_4"/NaOH/0°C Reaction:"#

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.

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Answer 2

Elias Aguila

OsO4/tBuOOH/HO^- is used for the oxidative cleavage of alkenes to form carbonyl compounds. KMnO4/NaOH at 0°C is commonly used for the oxidative cleavage of alkenes to form carboxylic acids.

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Answer from HIX Tutor

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