Dihydroxylation of Alkenes to give 1,2-diols (vicinal diols)
Description: Treatment of alkenes with osmium tetroxide (OsO4) leads to the formation of 1,2-diols (“vicinal diols”).
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there is both syn and anti addition possible, it would be helpful to cover that. Just like with +HX reactions, it seems you can add HO-OH make the subs add differently. In this case, on the same side, changing the stereochemistry.
With OsO4 only syn addition is possible.
It is possible to perform net anti dihydroxylation through 1) epoxidation, say with mCPBA, and then 2) opening the epoxide with a source of HO(-) such as NaOH.
On the “Oxidative cleavage of alkenes to ketones/carboxylic acids using KMnO4” page, the reaction looks a lot different. So why does it say on this page “Also note that cold, alkaline KMnO4 does exactly the same reaction”? Is this just for when it’s cold? Thanks in advance for the help!!
hey im no expert, but my orgo teacher made sure to make the distinction that cold KMnO4 will do this reaction – and warm concentrated KMnO4 will do oxidative cleavage. Hope this helps :)