L15 - Electrophilic Carbonyls 2

Question 1

Steps to forming an ester when the carbonyl is very reactive (acyl chloride)

Answer 1

• LP on O attacks C on C=O on OH
• e- move to O (O-)
• e- move to kick Cl out
  + loss of proton
  = ester

Question 2

Steps to making an ester with a carbonyl that isn’t very reactive (alcohol)

Answer 2

• use Cat HA to add proton
• LP on O attacks C on C=O
• e- move to O
• proton transfer to other OH
• LP on O moves to +ve O
• loss of proton
  = ester

Question 3

Steps to making an amide with a very reactive carbonyl (acyl chloride)

Answer 3

• LP on N attacks C on C=O
• e- moves to O (O-)
• e- moves to kick Cl out
• loss of proton
  = amide

Question 4

What forms when an alcohol reacts with amine?

Answer 4

Doesn’t form the amide
- forms a salt

Question 5

How does nature make anide bonds from COOH?

Answer 5

It uses atp
- LP on N attacks C on C=O
- e- moves to O, moves back to form db
- kicks out phosphate group

Question 6

Steps to the hydrolysis of an ester in acidic conditions

Answer 6

• protenated ester
• LP on O (H2O) attacks C=O
• e- moves to +ve O
• proton transfer
• LP on OH moves to kick acl group
  Reversible

Question 7

Steps to the hydrolysis of ester in basic conditions

Answer 7

• LP on OH attacks C on C=O
• e- moves to O (O-)
• e- moves to kick out OR
• H in the COOH transfers to OR
  Not reversible

Question 8

Steps to the hydrolysis of an amide in acidic conditions

Answer 8

• protenated amide
• LP on O (H2O) attacks C on C=O
• e- moves to +ve O
• proton transfer to NH2
• LP on OH kicks out NH3+
• loss of proton
  = COOH
  Not reversible

Question 9

Steps to the hydrolysis of an amide in basic conditions

Answer 9

• LP on OH attacks C on C=O
• e- moves to O
• e- moves to kick out NH2
  (Slow as poor LG)
• COOH
• loss of proton