300 likes | 502 Views
King Saud University Chemistry Department. Alcohols and Phenols. King Saud University Chemistry Department. Alcohols and Phenols. - Alcohols and phenols may be viewed as organic derivatives of water. H-O-H R-O-H Ar-O-H
E N D
King Saud University Chemistry Department Alcohols and Phenols 145 Chem
King Saud University Chemistry Department Alcohols and Phenols - Alcohols and phenols may be viewed as organic derivatives of water. H-O-H R-O-H Ar-O-H Water Alcohol Phenol - 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. 145 Chem
King Saud University Chemistry Department Classification and Nomenclature of Alcohols Alcohols are classified into: 145 Chem
King Saud University Chemistry Department IUPAC Name: • In the IUPAC system, alcohols are named according to the following rules: • 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 Chem
King Saud University Chemistry Department 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. Common name • 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 Chem
King Saud University Chemistry Department - Primary alcohol 145 Chem
King Saud University Chemistry Department • Secondary and tertiary alcohol 145 Chem
King Saud University Chemistry Department Phenol 1-Phenylmethanol Benzyl alcohol (common name) 2-Phenylethanol Ethan-1,2-diol Ethylene glycol (common name) 4-Methyl-2-cyclohexen-1-ol 145 Chem
King Saud University Chemistry Department Physical Properties of Alcohols 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. 145 Chem
King Saud University Chemistry Department The presence of the hydrogen bonding between alcohol molecules as a result of the high b.p. of alcohol. Alcohols are week acids. 145 Chem
King Saud University Chemistry Department Homework 145 Chem
King Saud University Chemistry Department Synthesis (Preparation) of Alcohols 1. From alkene 2. From – alkyl halid 145 Chem
King Saud University Chemistry Department 3. Reduction of aldehyde, ketone and carboxylic acid. 4. Addition of Grignard compounds to aldehyde and ketone. Tertiary alcohol Secondary alcohol Primary alcohol 145 Chem
King Saud University Chemistry Department Reactions of Alcohols • Reaction as acids (Breaking of oxygen- Hydrogen bond CO ـــــH) A. Salt Formation Sodium ethoxide B. Ester Formation 2. Reaction with CــــOH bond cleavage A. Elimination Reactions B. Substitution Reaction
King Saud University Chemistry Department 3. Oxidation Reactions 145 Chem
King Saud University Chemistry Department Nomenclature and acidity of Phenols 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). 145 Chem
King Saud University Chemistry Department • Introduction of electron-withdrawing groups, such as NO2 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 Chem
King Saud University Chemistry Department Synthesis of Phenols 145 Chem
King Saud University Chemistry Department Reactions of Phenols 145 Chem
King Saud University Chemistry Department Electrophilic Substitution Reaction CCL4 or CS2 145 Chem
King Saud University Chemistry Department Home Work 145 Chem
King Saud University Chemistry Department 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 Chem
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 Chem