Study Set Content:
Ammonia and primary amines (RNH2) add to aldehydes and ketones to yield
- IMINES (R2C=NR)
intermediates in synthesis and degradation of amino acids in the body are called
Schiff bases
intermediates in synthesis and degradation of amino acids in the body are called Schiff bases
Imines
- Nucleophilic addition of OH- to an aldehyde to give a tetrahedral intermediate, which expels hydride ion as a leaving group and is thereby oxidized rarely used today
Cannizzaro reaction
- Occur at the position next to the carbonyl group—the a position—and result in the substitution of an a hydrogen atom by an electrophile (E) through either an enol or enolate ion intermediate.
Carbonyl Alpha - substitution reactions
Take place between two carbonyl partners and involve a combination of a substitution and nucleophilic addition steps.
Carbonyl condensation reactions
One partner is converted into its enolate ion and undergoes an
_a_- substitution reaction
when it carries out a (blank) to the second partner
nucleophilic addition
A carbonyl compound with a hydrogen atom on its a carbon rapidly equilibrates with its corresponding enol (ene + ol; unsaturated alcohol) isomer.
Keto-Enol Tautomerism
Greek tauto meaning
the same
and meros meaning
part
Keto-Enol Tautomerism
is both catalyzed by
acid and base
the individual keto and enol isomers
Tautomers
- involves protonation of the carbonyl oxygen atom (a Lewis base) to give an intermediate cation that loses H+ from the carbon to yield the enol.
Acid catalysis
- occurs because the presence of a carbonyl group makes the hydrogens on the carbon weakly acidic.
Base-catalyzed enol formation
The protons at (blank) other positions aren't acidic because the resulting anions can't be resonance-stabilized by the carbonyl group.
beta (B), gamma (y), delta (),
Aldehydes and ketones are halogenated at α positions by reaction with
- C12, Br2, or 12 in acidic solution.
- in acetic acid solvent is most often used.
Bromine
- The most useful reaction of enolate ions
Alkylation of Enolate Ions
- occurs when the nucleophilic enolate ion reacts with an electrophilic alkyl halide in an SN2 reaction, displacing the halide ion in the usual way.
Alkylation
