L3 Alcohols, Ethers, Thiols (Functional Groups)

What are Alcohols

Organic compounds with a hydroxyl -OH group

Naming Alcohols

1. Identify longest C chain with OH group

2. Number the chain s.t. OH has lowest possible number (if there is a tie with position of OH groups, use the position of other substituents groups to break it)

3. Suffix “ol” is added for one OH, “diol'“ for two, “triol” for three

4. Identify other substituents and order them alphabetically

Polyalcohols

Alcohols with more than one OH group, can be named with the hydroxyl prefix

Types of alcohols

1. Primary

2. Secondary

3. Tertiary

Primary alcohols

Hydroxyl group is bonded to terminal carbon; carbon is attached to only one alkyl chain

Secondary alcohols

Hydroxyl group is bonded to a carbon attached to two alkyl chains

Tertiary alcohols

Hydroxyl group is bonded to a carbon attached to three alkyl groups

Properties of Alcohols

1. Polar (can form hydrogen bonds)

2. Higher BP

3. More soluble in polar solvents

4. Long chained alcohols have nonpolar (hydrocarbon portion) and polar (OH) portion

5. Allows them to dissolve both polar and nonpolar compounds

Reactions involving Alcohols

1. Hydration (addition)

2. Combustion

3. Elimination

Hydration (addition) reaction

Forms alcohols, follows Markovnikov’s Rule

Alkene + water —> alcohol

Combustion of Alcohols

Same as usually combustion

Elimination: Dehydration (condensation) reaction (Alcohols)

In certain conditions, alcohols can decompose to produce alkenes and water, H and OH are removed from neighbouring carbons, forms C=C and H₂O

Ethers

Molecules with C-O-C group, more polar than hydrocarbons, but no H to form hydrogen bonds

Naming Ethers

Name shorter hydrocarbon group, followed by oxy and join it to the alkane name of the longer hydrocarbon group. Be careful of branching ethers (show point of attachment)

Naming Ethers (simple)

ShortOxyLong

Reactions with Ethers

Condensation reactions

Condensation reaction (ethers)

Forms ether, two alcohols combine to form ether and water

Thiols

Organic compound that contains sulfhydryl (SH) group

Naming thiols

Add suffix thiol to the longest C chain

What is Special about Thiols

Have a very strong smell, found in skunks for example