Chapter 9- Carboxylic Acid Derivatives

Question 1

reactions to form amides, esters, and anhydrides

Answer 1

these are all carboxylic acid derivatives. each is formed by a condensation reaction with a carboxylic acid- a reaction that combines two molecules into one, while losing a small molecule.

Question 2

how are amides formed

Answer 2

by the condensation reaction of other carboxylic acid derivatives and ammonia or an amine

Question 3

how are esters formed

Answer 3

by the condensation reaction of carboxylic acids or anydrides with alcohols

Question 4

amide physical properties

Answer 4

boiling points may be lower or on same level as carboxylic acids (depending on whats attached, more H bonds the higher boiling point)

Question 5

fischer esterfication

Answer 5

under acidic conditions, mixtures of carboxylic acids and alcohols will condense into esters

Question 6

ester physical properties

Answer 6

usually have lower boiling points than their related carboxylic acids b/c they lack hydrogen bonding

Question 7

ester example in body

Answer 7

triacylglycerols

Question 8

what is the main requirement to form an anhydride

Answer 8

heat

Question 9

anhydride physical properties

Answer 9

have higher boiling points than their related carboxylic acids, based solely on their much greater weight.

Question 10

list the 3 carboxylic acids in order of reactivity (most to least reactive toward nucleophilic attack)

Answer 10

anhydrides, esters, carboxylic acids, amides

*essentially most to least electrophilic

Question 11

3 electronic effects that come into play with MCAT orgo

Answer 11

1. Induction- distribution of charge across sigma bonds, dipole can be created if 1 atom is more electronegative (ex: carbonyl reactivity)
2. Resonance and Conjugation- presence of alternating single and multiple bonds. all atoms involved are either sp2 or sp-hybridized** much more powerful than induction

Question 12

how are ring strain and reactivity related?

Answer 12

more ring strain = more reactive

Question 13

nucleophilic acyl substitution

Answer 13

nucleophilic attack of the carbonyl carbon with displacement of a leaving group.

Question 14

what happens when you expose an anhydride to water

Answer 14

it reverts back into carboxylic acids

Question 15

transesterification

Answer 15

when alcohols act as nucleophiles and displace the esterifying group on an ester… one ester transforming into another.

Question 16

amides and acidic conditions

Answer 16

amides can be hydrolyzed via nucleophilic substitution

Question 17

B-lactams

Answer 17

• cyclic forms of the least reactive type of carboxylic acid derivative
• more reactive than their straight-chain counterparts
• molecules with high levels of ring strain