Term
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Definition
| the anions that result from a strong base removing an alpha hydrogen from an aldehyde or a ketone |
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Term
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Definition
| the enolate formed when the base removes a hydrogen from the less-hindered alpha carbon which usually results in generating the less stable anion |
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Term
| At room temperature & in the presence of a proton source such as a slight excess of ketone starting material, equilibration of the kinetic with the more stable _____ enolate takes place |
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Definition
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Term
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Definition
| a species that can react at two different sites to give two different products; "two fanged"; comes from the Latin word "ambi" for "both" & "dens" for "tooth" |
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Term
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Definition
| a reaction that attaches an alkyl group to a reactive carbon |
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Term
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Definition
| the product of protonation of an enolate ion at the oxygen that creates an unsaturated alcohol |
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Term
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Definition
| when an enol (an unstable isomer of an aldehyde or ketone) rapidly converts into the carbonyl system |
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Term
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Definition
| the isomers involved in tautomerization |
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Term
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Definition
| the conversion of the keto into the enol form; has very small equilibrium constants for ordinary aldehydes & ketones because only traces of enol are present |
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Term
| Does treatment of a ketone with traces of acid or base in D2O solvent lead to the complete exchange of all the alpha hydrogens? |
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Definition
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Term
| Is the formation of enols/enolates reversible? |
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Definition
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Term
| 3 step mechanism of the acid-catalyzed halogenation of a ketone |
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Definition
1. enolization (this is the r.d.s.)
2. halogen attack
3. deprotonation |
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Term
| What is the result of base-catalyzed halogenation of a ketone? |
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Definition
| the reaction continues until it completely halogenates the same alpha carbon, leaving unreacted starting material |
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Term
| Why does alkylation of an enolate work best with only halomethanes or primary haloalkanes? |
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Definition
| the enolate ion is a very strong base, therefore E2 elimination converting the haloalkane into an alkene becomes a significant process |
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Term
| What is the ideal ketone for alkylation? |
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Definition
| has only one alpha hydrogen |
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Term
| Is alkylation of an enamine superior to alkylation of an enolate? |
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Definition
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Term
| Aldehyde reactions with NaOH, H2O, and low temperatures result in _____ formation |
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Definition
| aldol (name comes from ALDehyde & alcohOL) |
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Term
| Aldehyde reactions with NaOH, H2O, and heat result in _____ formation |
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Definition
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Term
| 3 step mechanism of aldol formation |
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Definition
1. enolate generation
2. nucleophile attack
3. protonation |
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Term
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Definition
| combining two molecules into one with the elimination of a molecule of water |
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Term
| crossed aldol condensation |
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Definition
| carrying out an aldol condensation between the enolate of one aldehyde & the carbonyl carbon of another |
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Term
| When can you efficiently synthesize a single aldol product from the reaction of two different aldehydes? |
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Definition
| when one of the aldehydes has no enolizable hydrogens |
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Term
| Is it possible to carry out aldol condensations between two carbonyl groups located in the same molecule? |
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Definition
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Term
| intramolecular aldol condensation |
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Definition
| carrying out aldol condensations between two carbonyl groups located in the same molecule; important in the synthesis of cyclic compounds (especially 5 and 6 membered rings) |
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Term
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Definition
| alpha,beta-unsaturated carbonyl |
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Term
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Definition
| molecules with two functional groups |
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Term
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Definition
| when several reagents add to the conjugated pi system in a 1,4-manner |
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Term
| What does the end result of conjugate addition appear to be? |
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Definition
| 1,2-addition of Nu-H to the carbon-carbon double bond |
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Term
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Definition
| empirical formula R2CuLi; may be prepared by adding two equivalents of an organolithium reagent to one of copper iodide (CuI) |
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Term
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Definition
| the reaction in which enolate ions undergo conjugate additions to an alpha,beta-unsaturated aldehyde or ketone |
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Term
| What is the Michael "acceptor" in a Michael reaction? |
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Definition
| the beta-carbon of the unsaturated carbonyl compound |
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Term
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Definition
| the synthetic sequence of a Michael addition followed by an intramolecular aldol condensation |
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