Return to Contents Chapter 15: Alcohols, Diols and Thiols Ch 15 contents

Oxymercuration-Demercuration of Alkenes
(review of Chapter 14)

alkene alkoxymercuration-demercuration to give an alcohol

Reaction type:  Electrophilic Addition

Summary

Related Reactions
MECHANISM FOR REACTION OF ALKENES WITH Hg(OAc)2 / H2O
Step 1:
The C=C p electrons act as the nucleophile with the electrophilic Hg and loss of an acetate ion as a leaving group, forming the mercurinium ion.
oxymercuration / demercuration of C=C
Step 2:
Water functions as a nucleophile and attacks one of the mercury substituted carbons resulting in cleavage of the C-Hg bond.
Step 3:
The acetate ion functions as a base deprotonating the oxonium ion to give the alcohol. This completes the oxymercuration part of the reaction.
Step 4:(mechanism not shown)
The hydride reduces the Hg off, creating a C-H bond while breaking the C-Hg bond. This is the demercuration part of the process.

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