Alcohols and Phenols 145 Chem1 King Saud University Chemistry Department

145 Chem2 King Saud University Chemistry Department - Alcohols and phenols may be viewed as organic derivatives of water. - Alcohols and phenols have a common functional group, the hydroxyl group, —OH. - In alcohols the hydroxyl group is attached to an alkyl group, —R. - In phenols the hydroxyl function is attached to an aromatic ring, Ar. Alcohols and Phenols H-O-H R-O-H Ar-O-H Water Alcohol Phenol

Alcohols are classified into: 145 Chem3 King Saud University Chemistry Department Classification and Nomenclature of Alcohols

In the IUPAC system, alcohols are named according to the following rules: 1.Select the longest continuous carbon chain that contains the -OH group. Replace the ending e of the alkane by the suffix –ol 2. If a molecule contains both an -OH group and a C=C or C-C triple bond, - The name should include both the hydroxyl and the unsaturated groups. -The -OH group takes preference before the double or triple bonds in getting the lower number. - If a compound contains both OH and a double or triple bond, choose the chain that include them both even if this is not the longest chain. 145 Chem4 King Saud University Chemistry Department IUPAC Name:

3. In the IUPAC system -The suffix diol is added to the name of the parent hydrocarbon when there are two OH groups. -The suffix triol is added when there are three OH groups. -listing the alkyl substitutents attached to the hydroxyl group, followed by the word alcohol. -Two OH groups on adjacent carbons are known as 1,2- glycols. 145 Chem5 King Saud University Chemistry Department Common name

145 Chem6 King Saud University Chemistry Department - Primary alcohol CH 3 OHCH 3 CH 2 OH CH 2 =CHCH 2 OH CommonMethyl alcoholEthyl alcohol Allyl alcohol IUPACMethanolEthanol 2-Propen-1-ol

145 Chem7 King Saud University Chemistry Department - Secondary and tertiary alcohol CommonIsopropyl alcoholCyclopentyl alcoholMethylcyclohexyl alcohol IUPAC2-PropanolCyclopentanol 1-Methyl-1-cyclohexanol

145 Chem8 King Saud University Chemistry Department 4-Methyl-2-cyclohexen-1-ol Phenol 1-Phenylmethanol Benzyl alcohol (common name) 2-Phenylethanol Ethan-1,2-diol Ethelene glycol (common name)

145 Chem9 King Saud University Chemistry Department Diols and triols are more soluble in water than monohydroxyalcohols. As the number of carbons in the alcohol increases, the solubility in water decreases. The boiling points increase with increase in molecular weights. Physical Properties of Alcohols

The presence of the hydrogen bonding between alcohol molecules as a result of the high b.p. of alcohol. Alcohols are week acids. 145 Chem10 King Saud University Chemistry Department

Homework 145 Chem11 King Saud University Chemistry Department

1. From alkene – alkyl halid – Grignard reagent. 145 Chem12 King Saud University Chemistry Department Synthesis (Preparation) of Alcohols

2. Reduction of aldehyde, ketone and carboxylic acid. 3. Addition of Grignard compounds to aldehyde and ketone. 145 Chem13 King Saud University Chemistry Department

A. Formation of Salt B. Formation of Esters 145 Chem14 King Saud University Chemistry Department Reactions of Alcohols 1. Dissociation of O-H Bond Sodium ethoxide

A. Elimination Reactions B. Substitution Reaction 145 Chem15 King Saud University Chemistry Department 2. Dissociation of C-O Bond

C. Oxidation Reactions 145 Chem16 King Saud University Chemistry Department

145 Chem17 King Saud University Chemistry Department Phenols are generally named as derivatives of the simplest member of the family, phenol (hydroxyl group attached directly to a benzene ring are called phenols). Nomenclature and acidity of Phenols

-Introduction of electron-withdrawing groups, such as NO 2 or CN, on the ring increases the acidity of phenols. - Alcohols and phenols have weak acidic properties. -Phenols are much stronger acids than alcohols. 145 Chem18 King Saud University Chemistry Department

145 Chem19 King Saud University Chemistry Department Synthesis of Phenols

145 Chem20 King Saud University Chemistry Department Reactions of Phenols

145 Chem21 King Saud University Chemistry Department Electrophilic Substitution Reaction

145 Chem22 King Saud University Chemistry Department Home Work

4) The IUPAC name of is: A) 4-Ethyl-5-heptyn-3-ol B) 4-Ethyl-5-heptan-3-ol C) 4-Ethyl-5-hepten-3-ol D) 4-Etyl-2-hepten-5-ol 5) The IUPAC name of is: A) 3-Methyl-1-bromocyclohexanol B) 2-Bromo-3-methylcyclohexanol C) 4-Bromo-2-methylcyclohexanol D) 3-Bromo-1-methylcyclohxanol 145 Chem23 King Saud University Chemistry Department

6) The common name of 2-methyl-2-propanol is: A) Allyl alcohol B) Isopropyl alcohol C) tert-Butyl alcohol D) Benzyl alcohol 7) The following reaction gives A) 4-Ethylphenol B) 2-Ethylphenol C) Ethylphenyl ether D) Ethylphenyl ketone 145 Chem24 King Saud University Chemistry Department

145 Chem25 King Saud University Chemistry Department Thank you for your attention