Chapter 19 Flashcards
despite their charge distribution, enolate anions react as … that create new … bonds, making enolate anions important for organic synthesis
carbon nucleophiles; C-C bonds
enolate anions react with haloalkanes in … reactions
SN2
in the aldol reaction, enolate anions derived from aldehydes or ketones react with a second molecule of … or … to give a … rxn and create a new C-C bond
aldehyde; ketone; carbonyl addition reaction
the mechanism of the base-catalyzed aldol rxns involves initial deprotonation of the alpha-H in base to create an … anion, which attacks another aldehyde or ketone molecule to give a carbonyl addition intermediate which in turn reacts with … to create a … produce and regenerates the original base
enolate; water; beta-hydroxy aldehyde or ketone
the mechanism of the acid-catalyzed aldol rxn involves an initial acid-catalyzed … to provide the … form; protonation of a second molecule on the carbonyl oxygen creates an electrophilic oxonium ion that is then attacked by the nucleophlic enol, followed by loss of a … to give the … product
keto-enol tautomerization; enol; proton; beta-hydroxy aldehyde or ketone
the beta-hydroxy aldehyde/ketone products of aldol rxns are easily dehydrated and lose H2O to give an …
alpha, beta-unsaturated aldehyde/ketone
the claisen condensation involves two ester molecules reacting in base to give a
beta-ketoester product
a dieckmann condensation is an … of a diester
intramolecular Claisen condensation
to become skilled at retrosynthetic analysis, it is important to recognize that the … and … functional groups are the characterstic products of an aldol rxn
alpha beta-unsaturated carbonyl; beta-hydroxy carbonyl
for retrosynthetic analysis, the … functional group is the characteristic product of claisen/dieckmann
beta-ketoester
enamines are formed through rxn of an aldehyde/ketone with a ..
secondary amine
enamines are important for synthesis bc the … is a nucleophile by virtue of conjugation of the C=C bond with the electron pair on nitrogen
beta-C
enamines resemble … and … in their rxns; yet harsh conditions are not required
enols; enolate anions
enamines can be alkylated on the beta c in an … rxn with … and …
SN2; methyl; primary haloalkanes
enamines can be acylated on the b-C by treatment with … and …
acid chlorides; acid anhydrides