Enols and Enolates – Part 2 | Organic Chemistry 3
Additional reactions of enols and enolates are studied in this chapter: halogenation of aldehydes and ketones, 1,2- and 1,4-additions of unsaturated carbonyls by organometallic reagents, Michael addition, Robinson annulation
Halogenation of Aldehydes and Ketones
Mechanism:
- Enolization:
- Halogen attack followed by deprotonation:
1,2- and 1,4-additions by Organometallic Reagents
Organolithium reagents (RLi): 1,2-addition
Gilman reagents (R2CuLi): 1,4-addition
Grignard reagents (RMgBr): 1,2 or 1,4-addition depending on reagent and substrate structure
Michael Addition
Mechanism:
Robinson Annulation
Mechanism:
- Michael addition:
- Intramolecular aldol condensation:
- Aldol dehydration: