C.A. derivatives reactions

Question 1

saponification

Answer 1

base catalysed hydrolysis of esters

Question 2

formation/ hydrolysis of lactones (cyclic esters)

Answer 2

formation: acid cat. ring formation from C.A. and OH
hydrolysis: base cat. ring breaking

Question 3

nucleophillic acyl sub

Answer 3

LG bonded to carbonyl carbon replaced by Nucleophile
* reversible if Nu also good LG

Question 4

hydrolysis of amides

Answer 4

amide -> C.A.
* acidic or basic conditions

Question 5

NH2 protecting group

Answer 5

amine (NH2) — pyridine(base) and acid chloride—–> amide [NH(C=O)]

Question 6

what does NH2 need a amide protecting group

Answer 6

prevents NH2 from turning into NH3 in acidic conditions ; changing from an EDG to a EWG

Question 7

hydrolysis of nitriles

Answer 7

nitriles -> C.A.
*basic conditions

Question 8

hydrolysis of acid chlorides and anhydrides

Answer 8

only need water because so reactive

acid chlorides: HCl and C.A.
anhydrides: 2 equ C.A.

Question 9

least to most reactive C.A. derivatives

Answer 9

nitriels, amides, esters/C.A….. ANHYDRIDES AND ACID CHLORIDESSSSS

Question 10

what makes carbonyl-LG structure more stable

Answer 10

• 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)

Question 11

what makes the LG more stable

Answer 11

base/nuc strength:
- delocalization of charge/ resonance
-electroneg: neg charge on MORE electroneg atom more stable/ favored

Question 12

overall uphill transformation

Answer 12

amide (less reactive) -> C.A. (more reactive)

Question 15

What can an acyl chloride thermodynamically favorable transform into

Answer 15

amide (amide + base)
ester (alcohol + base)
anhydride (carboxy)

Question 16

overall downhill transformation

Answer 16

acyl chlorides -> C.A.

Question 17

what can an acid anhydride thermodynamically favorable transform into

Answer 17

amide (amine)
ester (alcohol)

Question 18

what can an ester thermodynamically favorable transform into

Answer 18

amide (with NH3)

Question 19

what is the only reducing agent that can reduce C.A. and its derivatives

Answer 19

LiAlH4!!

*H2, Ni, pressure and heat can reduce nitriles

Question 20

what is a nitrile reduced to

Answer 20

amine

Question 21

what is an ester reduced to

Answer 21

alcohol (aldehyde intermediate)

Question 22

what is an amide reduced to

Answer 22

amine (imine intermediate)

Question 23

How can an aldehyde be synthesised and isolated from a C.A. der

Answer 23

acid chloride —H2, pd/c poisoned cat, pressure, heat —–>aldehyde

*less reactive reducing agent can only reduce acid chloride (very reactive) not ketone/aldehyde

Question 24

carbon nucleophiles that can react with C.A. derivatives

Answer 24

grignards, organolithium, organocuprates

Question 25

ester + grignard ->

Answer 25

tertiary alcohol

Question 26

ester + organolithium ->

Answer 26

tertiary alcohol

Question 27

how to turn a acid chloride into a ketone

Answer 27

1)R2CuLi (one r group with replace Cl)
2) acid workup