Chapter 18: Enols and Enolates

Reaction type : Conjugate addition, then intramolecular Aldol and finally an Elimination (!)

Summary

• A complex sequence that can be used to form bicyclic systems containing a substituted cyclohexenone system.
• These products are important systems in various natural products, for example within steriods.
• "Annulation" means "building a ring"
• The reaction is named after Sir Robert Robinson.
• The sequence involves the following steps:
• Michael addition of an enolate on a conjugated ketone
• An intramolecular Aldol reaction
• An elimination of an alcohol to give a conjugated ketone

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