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Hydroxylation of Alkenes

hydroxylation of alkenes

Reaction Type : Electrophilic Addition

Summary

cis-1,2-cyclohexanediol

QUESTIONS
What other reaction is commonly used as a functional group test for alkenes ? ANSWER
What is the oxidation state of the osmium in osmium tetroxide ? ANSWER
Is the osmium oxidised or reduced during the formation of the osmate ester ? ANSWER
What is the oxidation state of the potassium permanganate ? ANSWER

Related reactions

MECHANISM FOR REACTION OF ALKENES WITH OSMIUM TETROXIDE
Step 1:
The p electrons in the alkene act as a nucleophile forming a favourable 5 membered ring as a cyclic osmate ester as an intermediate. Note the origin of the cis stereochemistry.
hydroxylation of C=C by OsO4
Step 2:
The hydroxide liberates the cis-diol and the reduced osmium species.... this would then be reoxidised by the peroxide co-oxidant.

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© Dr. Ian Hunt, Department of Chemistry, University of Calgary