Exam 3 Flashcards
conditions for enolate to enol
H+
intramolecular aldol condensation
NaOEt, HOEt
crossed aldol condensation
NaOEt, HOEt
why can “crossed” aldol condensations only be used in limited cases?
- only one reaction partner is enolizable
- electrophlile must be used in excess to avoid self aldol
acidic aldol condensation
H3O+
retro aldol
alpha-beta unsaturated from enolate + carbonyl
what is the signature product of a claisen condensation?
beta-keto ester
ester to beta-keto ester
- NaOR’, R’OH
- H+ workup
what MUST be present in the starting ester to perform a classien condensation?
the starting ester must have 2 alpha protons
conditions for a retro claisen
NaOR, ROH
conditions for intramolecular claisen condensation
- NaOR, ROH
- H+ workup
how do we get this desired product in steps?
- enolize a dicarbonyl compound
2.alkylation at the alpha carbon
conditions for hydrolysis and decarboxylation of beta-ketone esters
1.NaOH, H2O
2.HCI, heat
what reaction occurs between a delocalized enolate (nuc) and an alpha-beta unsat’d carbonyl (elec)
micheal reaction
what is the signature product of a Micheal reaction?
1,5-dicarbonyl
conditions for a micheal reaction
1.NaOR, ROH
2.H+ w/u
steps for carbonyl to enol in acid
- protonate oxygen
- deprotonate H and delocalize it to oxygen
steps for carbonyl to enol in base
- base with deprotonate and delocalize e- onto the oxygen
- protonation by weak acid (water)
what is the intermediate for aldol condensation?
beta-hydroxy carbonyl
conditions aldehyde/ketone to imine
RNH2 ph=5
conditions aldehyde/ketone to enamine
R2NH2 ph=5
conditions for imine to aldehyde
H3O+ (hydrolysis)
conditions for enamine to ketone
H3O+ (hydrolysis)
conditions for ester to cbx acid
1.NaR
2.H+ workup
conditions for acid halide to cbx acid
H2O
what are two good enough LGs to get kicked out by LPP but not for Sn2 or E2
-OH or -OR
conditions for amide to cbx acid
H2O, H+ cat (acidic conditions)
conditions for nitrile to cbx acid
H2O, H+ cat (acidic conditions)
conditions for cbx acid to acid chlorides
SOCI2 (basic conditions)
conditions for cbx acid to ester
ROH, H+ (cat) (acidic conditions)
what conversion happens in a Fisher Esterification?
cbx acid to ester
conditions for acid chloride to amide
R-NH2, pyr
conditions for acid chloride to ester
ROH
what types of reagents when added to esters will act like nucleophiles and be added twice
organometallic or hydride reagents
what kind of functional groups are reactive with Grignards?
ketones
conditions for reduction of esters and acids
- LiALH4, Et2O
- H+ workup
conditions for amide to amine
- LiALH4, Et2O
- H+ workup
conditions for nitrile to amine
- LiALH4, Et2O
- H+ workup
conditions for primary alcohol to aldehyde
CrO3, pyr
conditions for primary alcohol to cbx acid
CrOs, H2O
conditions for secondary alcohol to ketone
CrO3, pyr
why cant a tertiary alcohol go through oxidation?
there are no hydrogens to remove
why are aldehydes more electrophilic than ketones?
Hyperconjugation!
delocalization of the sigma C-H electrons to pi*C=O
what are two hydride reducing reagents to go from aldehyde/ketone to secondary alcohol
NaBH4,ROH
or
1. LiAlH4, Et2O
2. H+ workup
what are two organometallic nucleophilic reagents to go from aldehyde/ketone to secondary alcohol
1.R’‘Li, Et2O
2. H+ w/u
or
1.R’‘MgX, Et2O
2. H+ w/u
conditions for hydrate formation in acid
H2O, H+cat
conditions for hydrate formation in base
NaOH, H2O
conditions for carbonyl group to cyanohydrin
NaCN, H2O
conditions for formation of hemiacetals under basic conditions
NaOR, ROH
conditions for formation of acetals under acidic conditions
ROH, H+ cat
conditions for formation of
cyclic acetals under acidic conditions
OH-c-c-OH , H+ (cat)
1,2 addition favors what kind of nucleophiles?
hard
1,4 addition favors what kind of nucleophiles?
soft
conditions for cyclic acetals to cbx acid
H3O+
what is the purpose of KOtBu, tBuOH?
to pull off protons
