Ch 17 orgo notes - Ch 17:Enols and Enolate Anions as...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch 17:Enols and Enolate Anions as Nucleophiles. Alkylation and Condensation Reactions Enols and enolate anions are nucleophiles and react with electrophiles The electrophile may be a halogen, an alkyl halide, or a carbonyl compound Enolate ions also add to double bonds that are conjugated w/ a carbonyl group When enolate anions react as nucs w/ electrophilic carbon atoms, C-C bonds are formed o Important for syntheses!! 17.1 Rxns of Enols and Enolates w/ halogens as electrophiles o ex, enol of acetone reacts w/ bromine to give 1-bromo-2-propanone o bromine is the electrophile that reacts w/ nucleophilic enol o the rate of halogenation depends only on the concentration of ketone o formation of the enol from the ketone is the rds 17.2 Reactions of Enolate Anions w/ alkyl halides as electrophiles o enolate anions react w/ alkyl halides in nucleophilic substituion rxns known as alkylation rxns o 2 resonance contributors of the enolate anion exist: the enolate ion has e- density and negative charge at two sites it is basic and nucleophilic at the alpha carbon and at the oxygen atom of the carbonyl group can be protonated or can react w/ electrophiles at either of these sites an anion that has the capacity to react at either of 2 positions is called an ambident anion where it reacts depends on reaction conditions generally, carbon electrophiles favor alkylation at the carbon atom o lithium diisopropylamide is a strong base but a poor nuc so fewer side products; deprotonates the ketone on the less substituted side (kinetic) o alkylation of esters enolate anions of esters can also be prepared using lithium
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 3

Ch 17 orgo notes - Ch 17:Enols and Enolate Anions as...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online