carbonyl reactivity Flashcards
most reactive carbonyl
acid chloride
what is the pKa of an acid chloride
-7
what makes an acid chloride more reactive than an acid anhydride
it has a more stable leaving group (Cl- more stable than ethyl ethanoate
what is more reactive out of an aldehyde and ketone and why
aldehyde because of there is only 1 positive inductive effect from the alkyl group, whereas a ketone has 2 positive inductive effects making it LESS electrophilic than the aldehyde
which is more reactive out of an ester and amide and why
both are unreactive due to mesomeric effects which REDUCES the electrophilic carbon. The ESTER is more reactive though as the O is more ELECTRONEGATIVE so more electronegativity is pushed back into the molecule, restoring some electrophilicness.
trans rotamer
r groups are one the same face (eg amides)
cis rotamers
r groups face away from each other (eg amides)
how do rotamers occur in amides
mesomeric effects restricting rotation
are amides basic, and why
no because of mesomeric effects, the lone pair overlaps with the pi cloud so they can’t accept a proton
rank order of amino acids (most reactive to least reactive)
acid chloride, acid anhydride, aldehyde, ketone, ester and amide
carbonyl without a leaving group + H2O
forms a hydrate
what makes something the major product
more stable
carbonyls without a leaving group + OH
forms ketals if R is a CH3 / acetals if R is an H
how does glucose exist in water
a cyclic hemiacetal
carbonyl without a leaving group + amine (condensation reaction)
imine
carbonyl with no leaving group + secondary amine
enamine (via hemiaminal)
how to make an ester with an acyl chloride
react with an alchol
how to make an ester with a carboxylic acid
react with an alcohol and acid catalyst (to make electrophile more electrophilic)
how to make an amide with an acid chloride
react with an amine
what does a carboxylic acid and amine make
a salt, NOT an amide
how does nature make amides
thioesters and acyphosphates
hydrolysis of an ester in acidic conditions does what to the electrophile
makes it more electrophilic, forms alcohol and carboxylic acid
hydrolysis of an ester in basic conditions forms…
an alcohol and carboxylate salt
where does the amide get protonated during acidic hydrolysis and why
the O because the lone pair on the N is unavailable due to mesomeric effects
products of acidic amide hydrolysis
carboxylic acid and ammonium
products of basic amide hydrolysis
ammonia and carboxylate salt
