1. 1 1435-1436 2014-2015 Alcohols and Phenols

2. Learning Objectives Chapter six concerns alcohols and phenols and by the end of this chapter the student will:  know the difference in structure between alcohols and phenols  Know the different classes of alcohols  Know how to name alcohols and phenols  Know the physical properties (solubility, boiling and melting points)  Know how hydrogen bonds are formed and its effect on boiling points of alcohols  Know the acidic properties of alcohols and phenols  know the different methods that can be used to prepare alcohols and phenols.  Know the chemical reactions of these compounds ( some reactions are review, others are extensions of the chemistry that will be discussed on chapters 8, 9 & 10 145 Chem. Alcohols and Phenols

3. 145 Chem. 3  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 directly attached to benzene ring H-O-H R-O-H or PhCH 2 OH Ph-O-H Water Alcohol Phenol Structure Of Alcohols and Phenols Alcohols and Phenols

4. according to the type of the carbon atom connected to the hydroxyl group (carbinol carbon) Alcohols are classified according to the type of the carbon atom connected to the hydroxyl group (carbinol carbon) into: 4 Classification and Nomenclature of Alcohols 145 Chem. Alcohols and Phenols

5. 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 cΞc bond;  Choose the chain that include both of them even if this is not the longest chain.  The name should include suffixes indicate presence of both the OH group and the unsaturated groups.  The OH group takes precedence over the double or triple bonds in getting the lower number.  Cyclic alcohols are named using the prefix cyclo-, the carbon bearing the hydroxyl group is assumed to take number 1. 3. The suffix diol is added to the name of the parent hydrocarbon when there are two OH groups. 4. The suffix triol is added when there are three OH groups 4. The suffix triol is added when there are three OH groups. 145 Chem. 5 NOMENCLATURE OF ALCOHOLS IUPAC Nomenclature Of Alcohols Alcohols are named according to the following rules: Alcohols and Phenols

6. 6 Common Nomenclature Of Alcohols  List the names of alkyl substituents attached to the hydroxyl group, followed by the word alcohol.  If two OH groups present on two adjacent carbons these known as glycols Primary alcohols CH 3 OHCH 3 CH 2 OH CH 2 =CHCH 2 OH CommonMethyl alcoholEthyl alcohol Allyl alcohol IUPACMethanolEthanol 2-Propen-1-ol 145 Chem. Alcohols and Phenols

7. 7 Secondary and tertiary alcohols CommonIsopropyl alcoholCyclopentyl alcoholMethylcyclohexyl alcohol IUPAC2-PropanolCyclopentanol 1-Methyl-1-cyclohexanol 145 Chem. Alcohols and Phenols

8. 8 4-Methyl-2-cyclohexen-1-ol 1-Phenylmethanol Benzyl alcohol (common name) 2-Phenylethanol Ethan-1,2-diol Ethelene glycol (common name) Examples Examples 145 Chem. Alcohols and Phenols

9. Examples Examples 145 Chem. Alcohols and Phenols

10. 145 Chem. 10 Physical Properties of Alcohols 1) Boiling Points of Alcohols  The boiling points increase with increase in molecular weights. Alcohols have higher boiling points(b.p.) than alkanes of similar weight this is due to the presence of hydrogen bonds between molecules of alcohols. Alcohols have higher boiling points(b.p.) than alkanes of similar weight this is due to the presence of hydrogen bonds between molecules of alcohols. hydrogen bond Alcohols and Phenols

11. 11 145 Chem. Alcohols and Phenols 2) Solubility Of Alcohols and Phenols Alcohol and water contain hydroxyl group that can form hydrogen bonds.  The hydroxyl group is hydrophilic “water loving”  The alkyl group of alcohols is hydrophobic “ water hating”  As the number of the –OH group in alcohol increases, the solubility in water increases.  Diols and triols are more soluble in water than monohydroxyalcohols.  The lower alcohols are completely miscible with water  As the number of carbons in the alcohol increases, the solubility in water decreases. Homework

12. 12 3) Acidic Properties of Alcohols: Alcohols are very weak acids The hydroxy proton of an alcohol is weakly acidic A strong base can abstrate the hydroxyl proton to give an alkoxide ion. Electron-withdrawing group (-I) increase acidity Electron-releasing group (+I) decrease acidity Alcohols and Phenols 145 Chem.

13. 13 Synthesis (Preparation) of Alcohols 1- Hydration From Alkenes 2- From alkyl halide nucleophilic substitution (elimination of HX using base gives alkene) Alcohols and Phenols 1- Oxidation of Alkenes or aq. KOH

14. 145 Chem. 14 3- Reduction of aldehydes, ketones and carboxylic acids Alcohols and Phenols

15. 145 Chem. 15 4- Addition of Grignard compounds to aldehydes & ketones Tertiary alcohol Ketone Secondary alcohol Primary alcohol Methanal formaldehyde Alcohols and Phenols

16. A. Formation of Salt (Alkoxide formation) 145 Chem. 16 1. Dissociation of O-H Bond Sodium ethoxide Reaction of Alcohols B. Formation of Esters H+H+ H + / H 2 O Reaction as acids (Breaking of oxygen- Hydrogen bond CO ـــــH) Alcohols and Phenols

17. A. Elimination Reactions 145 Chem. 17 B. Substitution Reaction 2. Dissociation of C-O Bond Reaction with CــــOH bond cleavage Alcohols and Phenols

18. 145 Chem 18 C. Oxidation Reactions Alcohols and Phenols

19. 145 Chem.19 Phenols (compounds having hydroxyl group directly attached to a benzene ring ) are generally named as derivatives of the simplest member of the family, phenol Acidity :  Alcohols and phenols have weak acidic properties.  Phenols are much stronger acids than alcohols.  Introduction of electron-withdrawing groups, such as NO 2 or CN, on the ring increases the acidity of phenols. Nomenclature and acidity of Phenols Alcohols and Phenols

20. 20 145 Chem. Alcohols and Phenols

21. 145 Chem. 21 Synthesis of Phenols Alcohols and Phenols

22. 145 Chem. 22 Reactions Phenols Ethers formation Alcohols and Phenols

23. 145 Chem. 23 2. Electrophilic Substitution Reactions Alcohols and Phenols

24. 145 Chem. 24 Home Work Alcohols and Phenols

25. 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. 25 6) The most acidic compound is: Alcohols and Phenols

26. 7) The common name of 2-methyl-2-propanol is: A) Allyl alcohol B) Isopropyl alcohol C) tert-Butyl alcohol D) Benzyl alcohol 8) The following reaction gives A) 4-Ethylphenol B) 2-Ethylphenol C) Ethylphenyl ether D) Ethylphenyl ketone 145 Chem. 26 Alcohols and Phenols

27. 9) The major product for the following reaction is 10) The product of the reaction shown below is 11) Which of the following compounds has the highest boiling point? Alcohols and Phenols

28. Thank You for your kind attention ! Questions? Comments 28 Alcohols and Phenols