C.A. derivatives reactions Flashcards
saponification
base catalysed hydrolysis of esters
formation/ hydrolysis of lactones (cyclic esters)
formation: acid cat. ring formation from C.A. and OH
hydrolysis: base cat. ring breaking
nucleophillic acyl sub
LG bonded to carbonyl carbon replaced by Nucleophile
* reversible if Nu also good LG
hydrolysis of amides
amide -> C.A.
* acidic or basic conditions
NH2 protecting group
amine (NH2) — pyridine(base) and acid chloride—–> amide [NH(C=O)]
what does NH2 need a amide protecting group
prevents NH2 from turning into NH3 in acidic conditions ; changing from an EDG to a EWG
hydrolysis of nitriles
nitriles -> C.A.
*basic conditions
hydrolysis of acid chlorides and anhydrides
only need water because so reactive
acid chlorides: HCl and C.A.
anhydrides: 2 equ C.A.
least to most reactive C.A. derivatives
nitriels, amides, esters/C.A….. ANHYDRIDES AND ACID CHLORIDESSSSS
what makes carbonyl-LG structure more stable
- shorter sigma bond length (pi bond character through resonance)
- LG and C have similar orbital size (2p) so more overlap
-electroneg of LG: more electroneg the element the more reactive (most stable anion)
what makes the LG more stable
base/nuc strength:
- delocalization of charge/ resonance
-electroneg: neg charge on MORE electroneg atom more stable/ favored
overall uphill transformation
amide (less reactive) -> C.A. (more reactive)
What can an acyl chloride thermodynamically favorable transform into
amide (amide + base)
ester (alcohol + base)
anhydride (carboxy)
overall downhill transformation
acyl chlorides -> C.A.
what can an acid anhydride thermodynamically favorable transform into
amide (amine)
ester (alcohol)
what can an ester thermodynamically favorable transform into
amide (with NH3)
what is the only reducing agent that can reduce C.A. and its derivatives
LiAlH4!!
*H2, Ni, pressure and heat can reduce nitriles
what is a nitrile reduced to
amine
what is an ester reduced to
alcohol (aldehyde intermediate)
what is an amide reduced to
amine (imine intermediate)
How can an aldehyde be synthesised and isolated from a C.A. der
acid chloride —H2, pd/c poisoned cat, pressure, heat —–>aldehyde
*less reactive reducing agent can only reduce acid chloride (very reactive) not ketone/aldehyde
carbon nucleophiles that can react with C.A. derivatives
grignards, organolithium, organocuprates
ester + grignard ->
tertiary alcohol
ester + organolithium ->
tertiary alcohol
how to turn a acid chloride into a ketone
1)R2CuLi (one r group with replace Cl)
2) acid workup
