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 OH OH 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