13. Chapter 15 Flashcards Preview

Chem 250 > 13. Chapter 15 > Flashcards

Flashcards in 13. Chapter 15 Deck (12)
Loading flashcards...
1
Q

What are the addition-elimination reactions carboxylic acids undergo?

A

Addition of nucleophile and elimination of leaving group

Slide 2

2
Q

What is the formula of carboxylic acid derivatives?

A

RCOX
X is a group with a heteroatom bonded to the carbon atom of the carbonyl group

Slide 4-5

3
Q

What results when a nucleophile in its conjugate base form reacts with chlorides or anhydrides?

A

Replaces Cl with nucleophile

Slide 6

4
Q

What does a strong base have to do with alkoxides?

A

Strong base (NaH) is normally used to generate the required alkoxide

Slide 6

5
Q

What is a saponification reaction?

A

Ester hydrolysis in basic conditions
Esters can be converted to acids using NaOH or KOH in water in a saponification reaction

Slide 7

6
Q

How to esters convert to amides?

A

Direct conversion of esters into amides is feasible only at high temperatures

Slide 11

7
Q

What is Fischer esterification?

A

Formation of esters by heating and alcohol and carboxylic acid together with a small amount of a strong acid catalyst

Continuous removal of water as it is formed by distillation will drive the reaction equilibrium to the right and this favour product formation

Slides 12-13

8
Q

What is water hydrolysis?

A

Ester hydrolysis in acidic conditions (also know as acid catalyzed hydrolysis of an Ester)
Excess water can be added to an ester hydrolysis to favour the production of a carboxylic acid

Slide 14

9
Q

What is transesterification?

A

Esters can be transformed into other esters
The mechanism is identical to Fischer esterification, with ester in place of carboxylic acid
Removal of methanol will help to drive esterification

Slide 15

10
Q

How can carboxylic acids be converted to other acyl groups?

A

Carboxylic acids can be converted to other acyl groups by using a dehydrating agent, a reagent that absorbs water
Such reagents convert the OH of the acid into a leaving group

Slide 16-17

11
Q

How does acid chloride convert to all other carboxylic acid derivatives?

A

Slide 18

12
Q

How do you reduce carboxylic acid derivative with LiAlH4 (nucleophilic hydride reagents)?

A

Slide 19-20