Alcohols

Question 1

Phenol

Answer 1

Aromatic ring with a hydroxyl group

Particularly acidic because of resonance within the phenol ring

Question 2

When a benzene ring contains two substituents we denote by
___ when they are adjacent
___ when they have 1 carbon separating them
___ when they are on opposite sides of the ring

Answer 2

Ortho-o
Meta-m
Para-p

Question 3

What increases boiling point:

Answer 3

Hydrogen bonding from alcohols
Increased number of hydroxyl groups
Increased length of alkyl chain

Question 4

Hydrogen bonding can increase:

Answer 4

Boiling point, melting point, solubility in water

Question 5

When does hydrogen bonding occur

Answer 5

When hydrogen is bound to an EN atom such as F O N creating extreme polarity

Question 6

Describe the oxidation of a primary alcohol by PCC? By other oxidizing agents

Answer 6

With PCC it is oxidized to an aldehyde and goes no further because pyridinium chlorochromate lacks the water necessary to hydrate aldehyde further
Other oxidizing agents allow thee aldehyde to be hydrated to form a geminal diol which is oxidized to a carboxylic acid

Question 7

Describe the oxidation of secondary alcohols

Answer 7

Oxidized to ketones by PCC or any other strong oxidizing agent
Strong oxidizing agents may include sodium and potassium dichromate salts

Question 8

What is Jones oxidation

Answer 8

Chromium trioxide (CrO3) is used as an oxidizing agent in dilute sulphuric acid in acetone 
Oxidizes primary alcohols to carboxylic acids and secondary alcohols to ketones

Question 9

What are the two main functions of mesylates and tosylates

Answer 9

Reacted with alcohols to turn hydroxyl groups into better leaving groups for nucleophilic substitutions
To serve as protecting groups when we do not want alcohols to react as they do not react with many of the reagents that would attack alcohol

Question 10

Describe how alcohols can be used as a protecting group

Answer 10

Aldehydes and ketones can be reacted with to equivalents of alcohol or a diol to from acetals or ketals
Acetals and ketals are not reactive with strong reducing agents like lithium aluminum hydride and therefore protect the aldehyde and ketone from reaction
After the reducing other functional groups the ketal or acetal can be reverted back to carbonyl with aqueous acid - deprotection

Question 11

What happens when you treat a phenol with an oxidizing agent?

Answer 11

You get a quinone

Question 12

What are the properties of quinones

Answer 12

They have a conjugated ring system so they are resonance stabilized electrophiles (not necessarily aromatic)

Question 13

What is the biological function of quinones? Give some examples

Answer 13

They act as electron acceptors in the ECT
Eg. Phylloquinone (vitamin k1) important for photosynthesis and carboxylation of clotting factory
Menaquinones (vit k2)

Question 14

What are hydroxyquinones? How are they formed?

Answer 14

Share the same ring and carbonyl backbone as quinones but they have the addition of 1 or more hydroxyl groups
They are formed by oxidizing quinones

Question 15

Ubiquinone

Answer 15

Biologically active quinone. Aka coenzyme Q. It is an electron carrier in complexes I II III of the ECT. Most oxidized form

Question 16

Ubiquinol

Answer 16

Reduced molecule of ubiquinone after it has accepted e- in the ECT