Carboxylic Acid Derivatives

Question 2

Carboxylic Acid Derivatives

Answer 2

Amides, Esters, and Anhydrides

Formed through condensation reactions (Combining two molecules into one while losing a molecule of water)

Question 3

Where does the water come from when forming carboxylic acid derivatives

Answer 3

The hydroxyl group of the carboxylic acid

A hydrogen associated with the incoming nucleophile

Question 4

Amides (Formula and Synthesis)

Answer 4

RCONH2

Synthesized by the reaction of other carboxylic acid derivatives with either ammonia or an amine

Question 5

Why do only primary or secondary amines undergo the reaction to form an amide

Answer 5

The loss of hydrogen from the amine is required for the reaction to take place

Question 6

Amide nomenclature

Answer 6

Replace -oic acid with -amide
Alkyl subs on N are named as prefixes and location specified by N-
Cyclic amides are lactams

Question 7

Lactams

Answer 7

cyclic amides

Named according to the carbon atom bonded to the nitrogen

Question 8

B-lactams: What is it? How many membered ring? Where is bond? Draw it?

Answer 8

Cyclic amides
4 membered rings
Contain bond between B-carbon and nitrogen

Question 9

Gamma Lactam

Answer 9

5-membered nitrogen-containing ring
as bond between gamma carbon and nitrogen

Question 10

Delta and Epsilon Lactam: Draw them. Bond?

Answer 10

Bond between delta carbon and nitrogen

Bond between epsilon carbon (5) and nitrogen

Question 11

How are amides synthesized

Answer 11

Carboxylic acid and amine or ammonia with H2O.

Can be two amino acids

Question 12

Properties of Amides

Answer 12

Boiling points may be lower or on the same level as boiling point of carboxylic acid.

Question 13

Esters

Answer 13

RCOOR

Question 14

ester nomenclature: Linear and cyclic

Answer 14

Esterifying group (sub bonded to oxygen) as a prefix and the suffix -oate replaces -oic acid.

Cyclic esters are lactones and named like lactams with the name of the precursor acid molecule also included.

Question 15

B-propiolactone

Answer 15

Question 16

How are ester synthesized (2)? What is that known as?

Answer 16

Carboxylic acid and alcohol. Fischer Esterification.

Also can do anhydrides and alcohol

Question 17

Fischer esterification

Answer 17

C=O make H bond to H.

Alcohol O attacks C on C=O and pushes double bond electrons to O and attaching alcohol by O to make tetrahedral intermediate.

OH of carboxylic acid attacks H of added alcohol to form OHH.

O-H bond from first step attacks central C and water leaves to form COOR

Question 18

Properties of Esters

Answer 18

Lack hydrogen bonding
Lower boiling point than other CA

Question 19

Triacylglycerol

Answer 19

Include three ester bonds between glycerol and fatty acids

Question 20

Anhydride

Answer 20

R(C=O)O(C=O)R

Question 21

How are anhydrides formed?

Answer 21

Condensation of two carboxylic acids

Question 22

Anhydride Formation Mechanism

Answer 22

O of O-H of one CA1 hits C of other CA2 which pushes double bond electrons to O and connects C-O.
H jumps from OH of CA1 and forms H20 with OH of CA2
O kicks electrons down and causes water to leave to form anhydride

Question 23

How are symmetrical anhydrides named?

Answer 23

Symmetrical anhydrides are named by replacing acid with anhydride

Question 24

How are cyclic anhydrides formed? How is the reaction driven?

Answer 24

Formed by heating CA
Reaction driven forward by increased stability of the newly formed rings and H2O leaves

Question 25

How are asymmetrical anhydride named?

Answer 25

Asymmetrical name both chains with -oic end and add anhydride.

Question 26

Anhydride Properties

Answer 26

Have higher boiling points than their related carboxylic acids due to weight

Question 27

In Nu substitution, most to least reactive towards nucleophiles

Answer 27

Acid Chloride, Anhydrides, Esters, Carboxylic acids, and Amides

Question 28

Steric Hindrance

Answer 28

Describes when a reaction cannot proceed because of substituents crowding the reactive site

Question 29

Protecting groups

Answer 29

such as acetals or ketals can be used to increase steric hindrance or otherwise decrease reactivity of a particular portion of molecule.

Question 30

Induction

Answer 30

Refers to uneven distribution of charge across a sigma bond because of difference in electronegativity

The more electronegative groups in a carbonyl containing compound, the greater the reactivity

Question 31

Conjugations: What does it refer to? What does it create?

Answer 31

Refers to the presence of alternating single and multiple bonds

Creates delocalized pi electron bond above and below the plane of the molecule.

Question 32

Conjugation: How do electrons have stability?

Answer 32

Electrons experience resonance through the unhybridized p-orbitals increasing stability

Question 33

Conjugated compounds are more or less reactive? Why?

Answer 33

More reactive b/c they can stabilize their transition states

More susceptible to nucleophilic attack

Question 34

Ring Strain: Increased strain, causes? What is a molecule that has a lot of ring strain? What is ring strain due to?

Answer 34

Increases reactivity.
B-lactam.
Due to torsional from eclipsing interactions and angle strain from compression bond angles below 109.5

Question 35

How can ring strain be increased? What does ring strain make up?

Answer 35

By attaching another ring.
Core of antibiotics.

Question 36

Nucleophilic Acyl Substitution Reactions

Answer 36

All CA derivative can undergo this.

Question 37

Anhydride Cleavage

Answer 37

Cleaved by the addition of a nucleophile

If ammonia then results in an amide and a CA
If alcohol as nuc then results in an ester and a CA
If water then results in two CAs

Question 38

Transesterification

Answer 38

The exchange of one esterifying group for another on an ester
Nucleophile is alcohol

Question 39

Hydrolysis of Amides

Answer 39

Amides can be hydrolyzed to CA under strong acidic or basic condition
The attacking nucleophile is water or a hydroxide ion