Orgo 2 Midterm Carboxylic Acid Derivatives

Which have a higher boiling point? Carboxylic acids or alcohols?

Carboxylic acids

Which conditions are carboxylic acids produced in?

Acidic Conditions

Which conditions will a carboxylate ion be produced in?

Basic

If a carboxylic acid is treated with water, what will the product be?

A carboxylate ion

What is the Pka of this structure?

4.19

What is the Pka of this carboxylic acid?

4.76

What is the Pka of this carboxylic acid?

4.87

Does Pka increase or decrease with each additional chlorine substituent?

Decrease

Why do carboxylic acids undergo nucleophilic acyl substitution?

Because Z can be more readily converted into a good leaving group whereas H and R cannot

What are the methods that can be used to prepare carboxylic acids?

• Na2Cr2O7/ H2SO4, H2O

• H3O+/ heat specifically with RCN

• Reaction of a grinard with CO2

Which reaction allows to go from an acid chloride to a ketone?

A Gilman Reagent (R2CuLi)

Which carboxylic acid derivative is the most reactive and why?

Acid halides because there is a lot of induction and resonance

Which carboxylic acid derivatives are the least reactive and why?

Amides because there is not a lot of induction or resonance

List the carboxylic acid derivatives most to least reactive.

Acid halides, Anhydrides, Esters, Amides

How can you prepare an acid chloride from a carboxylic acid?

SOCl2

How are carboxylic acids prepared from Acid halides?

• H2O, pyridine

How can a reduction of an acid chloride be carried out?

Forms a primary alcohol:

• Xs LiAlH4

• Xs NaBH4

Forms a tertiary alcohol:

• RMgBr

To stop the reduction at an aldehyde:

• LiAl(OR)3H

How can symmetrical anhydrides be formed?

By heating carboxylic acids

How to prepare Anhydrides from carboxylic acids?

By reacting it with an acid chloride

What are acetic anhydrides used for?

to acetylate an amine or an alcohol to make an ester or an amide

What are the ways that esters can be prepared?

• Carboxylate reacted with NaOH/ CH3I (or another alkyl halide) in an SN2 rxn

• Fischer Esterification (reacting a carboxylic acid with an alcohol with an acid catalyst)

• Treating an acid chloride with an alcohol (ROH/Pyridine)

How can esters produce a carboxylic acid?

• Saponification (Esters undergo hydrolysis under basic conditions) (NaOH/H3O+)

• H3O+

How can esters form amides?

Xs NH3

What are the ways to reduce esters?

To form two alcohols:

• using LiAlH4

To control a reduction to form an aldehyde:

• DIBAH

To produce a tertiary alcohol:

• Grignard Reagents

How can the reduction of carboxylic acids happen?

• LiAlH4

• NOT NaBH4

• BH3*THF

What can prepare amides?

Any of the other carboxylic acids

How can an amide form a carboxylic acid?

Under acidic conditions: H3O+ & Heat

Under basic conditions: NaOH, heat & H3O+

What is used in the reduction of Amides?

Xs LiAlH4

How can Nitriles be prepared?

• Alkyl halide and NaCN

• dehydration of a primary alcohol and then using SOCl2

How do Nitriles form Carboxylic Acids?

• Nitriles in aqueous conditions first form amides and then are further hydrolyzed to yield a carboxylic acid

• uses (H3O+/heat) twice

• Nitriles in basic conditions use NaOH, H2O/ H3O+ to directly form a carboxylic acid

What is the difference in carboxylic acid formation under acidic vs basic conditions

In basic conditions a carboxylic acid will form a carboxylate ion so it needs H3O+ as a second reactant to form the carboxylic acid. In acidic conditions, the H3O+ only really needs to appear once.

How can a reduction of a nitrile occur?

Xs LiAlH4

How can a Nitrile a Ketone?

Using a Grignard Reagent

What is this reaction called?

Transesterification