Alcohols & Phenols

Alcohols & Phenols

Alcohol – alkyl chain attached to an –OH R-OH • Phenol - aromatic attached to an –OH

Nomenclature • 1. Name the longest chain of carbons which includes the carbon with the hydroxyl group. • a. Remove the final ”-e”. • b. Add the ending “-ol”. • 2. Number the position of the hydroxyl group by numbering the carbon atom to which it is attached.

Nomenclature Examples • 1. • 2. • 3.

4. • 5. • 6.

7. • NOTE – OH group takes precedence over alkyl groups & double & triple bonds • 8. • 9.

3. Some phenols are known by their common names. phenol 1-naphthol o-cresol m-cresol p-cresol catechol resorcinol hydroquinone

4. Most substituted phenols are named as derivatives of the parent compound. Ex. 1 Ex. 2

5. In highly substituted alcohols & phenols, the OH group is considered a constituent of a larger compound and called a hydroxy group. Ex. 1 OH OHOH CH2==CH--CH--CH--CH--C--CH3 CH3-C-CH3 CH3 CH3

Ex. 2

Classification of Alcohols • Based on whether the hydroxyl group is attached to a carbon that is bonded to one, two or three other carbons • Primary (1°) • Secondary (2°) • Tertiary (3°)

Physical Properties of Alcohols • Have unusually high boiling points for molecules of their molecular weight because energy is required to break hydrogen bonds as well as to vaporize the molecules • Lower alcohols are soluble in water • When the alkyl group is 5 or more carbons long, the molecule begins to act more like a hydrocarbon and less like an alcohol – solubility falls of sharply • Alcohols are weaker acids than water • Phenols are stronger acids than water

Alcohols & Phenols