Carboxylic Acid Properties and Reactions

Question 1

What are the ways in which carboxylic acids can be made (WITHOUT using a carboxy. acid derivative)?

Answer 1

3 overall methods:

1) Oxidation of 1° ROH (with aq. ox. agents)

2) Carboxylation of Grignard (RMgBr + CO₂)

3) Hydrolysis of Nitrile (RCN + Basic or acidic conditions)

Question 2

1° ROH +

KMnO₄
———————–>
NaOH

Answer 2

Carboxylic Acid

Question 3

1° ROH +

Na₂O₂Cr₇
——————————————>
H₂SO₄, acetone

Answer 3

Carboxylic Acid

Question 4

Synthesis of RCOOH from 1° ROH: Reactants

Answer 4

KMnO₄
———————–>
NaOH

or

Na₂O₂Cr₇
——————————————>
H₂SO₄, acetone

Question 5

Synthesis of RCOOH using Grignard: Reactants

Answer 5

Grignard (R-MgBr) +

O=C=O
———————–>
H₃O⁺

Question 6

Synthesis of RCOOH by Carboxylation of Grignard: Process

Answer 6

1) Mg carbon on the grignard attacks the center carbon of CO₂ (O=C=O_

= An alkoxide forms on one of the CO₃ oxygens with the center carbon now having an added R chain

2) The alkoxide protonates using H₃O⁺

Question 7

Synthesis of RCOOH by nitrile hydrolysis (BOTH types): Reactants

Answer 7

Acidic:

H₃O⁺
——————->
H₂O

Basic:

NaOH
——————->
H₂O

Question 8

In the synthesis of an RCOOH from nitrile hydrolysis, what is the intermediate formed in BOTH the acidic and basic hydrolysis reactions?

Answer 8

An AMIDE

Question 9

Do carboxylic acids react with grignard reagents?

Answer 9

NO

Question 10

How can we rank carboxylic acids by their acidity?

Answer 10

By the stability of their conjugate bases (RCOO-)

Question 11

What factors increase acidity of a carboxylic acid?

Answer 11

Any modulations to a carboxylic acid that increase the ability for (-) charge to be stabilized in the RCOO- (conj. base)

–> Inductive effects (> # of EWGs closer to the (-) oxygen)

–> EWGs with greater electronegativity!