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Reactions of Enols, Enolates, Enones
(Carey, Chap. 18) |
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| Reaction | Product | Notes | |||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 
| Keto-enol tautomerism K usually << 1, but fast 
| alpha halogenation via enol 
alpha alkylation; | via enolate anion; must use very strong base (to get 100% enolate); R'' must be 1o 
| beta-dicarbonyl alkylation; alkoxide base strong enough; R'' can be 1o or 2o 
| alpha alkylation via enamine; R''X must be activated halide (benzyl, allyl, alpha to C=O) 
| simple aldol condensation; equilibrium; K > 1 for aldehydes only 
| aldol with dehydration; prep of conjugated enone works with alde. or ketone 
| mixed aldol condensation; R'' & R''' must have no alpha H's 
| mixed aldol condensation; beta-dicarbonyl cpd gives enolate anion exclusively 
| intramolecular aldol; 5 or 6 memb. rings only 
| 1,2-addition major; NaBH4 gives both 1,2- & 1,4-addition (mixtures) 
| 1,2-addition major; RMgX gives both 1,2- & 1,4-addition (mixtures) 
| conjugate addition (1,4-) only 
| conjugate addition (1,4-) only 
| Michael reaction (conjugate addition); with beta dicarbonyl enolate 
| Robinson annelation: Michael rxn to methyl vinyl ketone, then intramolecular aldol condensation. | ||||||||||||||||||||||||||||||