Alcohols Alcohols Contain a hydroxyl group (-OH). Phenols Contain a benzene ring with a hydroxyl group (-OH). OH

Naming Alcohols CH4 methane CH3─OH methanol CH3─CH3 ethane CH3─CH2─OH ethanol

Naming Alcohols Step 1- Identify the root Step 2 – Identify the suffix Select the longest carbon chain that contains the -OH group. Name the parent alkane. Step 2 – Identify the suffix Number from the end nearest -OH group. The suffix of an alcohol always ends with –Ol. Indicate the position of each hydroxyl group. If more than one -OH group place a prefix (di, tri, tetra) at the beginning of the suffix Step 3- Identify the prefix Name and number any branches as you would for a hydrocarbon Step 4- Name the compound Combine the prefix, root, and suffix to name the compound. If the suffix begins with a vowel, drop the “e” on the end of the parent alkane.

Name the following alcohol Parent alkane: heptane Suffix: -2,3-diol Prefix: 4-ethyl Name:4-methylheptane-2,3-diol

Name the following alcohol Root: hexane Suffix: -1-ol Prefix:3-methyl Name: 3-methylhexan-1-ol

Naming Alcohols CH3─CH2─CH2─OH propan-1-ol OH │ CH3─CH─CH3 propan-2-ol │ │ CH3─CH─CH2─CH2─CH─CH3 5-methylhexan-2-ol 3 2 1 3 2 1 6 5 4 3 2 1

Naming Alcohols OH │ CH3─CH─CH2─CH3 butan-2-ol CH3 CH3─CH─CH ─CH2─OH 3-chloro-2-methylbutan-1-ol CH3─C─CH2─OH 2,2-dimethylpropan-1-ol 1 2 3 4 Cl 4 3 2 1 CH3 3 2 1

Draw the condensed structural formula for 4-methylpentane-1,2-diol Root: 5 carbons Suffix: OH groups on C1 and C2 Prefix: methyl on C4

Different types of Alcohols Primary (1º) Secondary (2º ) Tertiary (3º) H CH3 CH3 │ │ │ CH3─C─OH CH3─C─OH CH3─C─OH H H CH3 1 C 2 C 3 C attached attached attached to C-OH to C-OH to C-OH

Physical Properties of Alcohols Alcohols are polar molecules (because of O-H and C-O). Hydrogen bonding between alcohols molecules. Have higher boiling points than Alkanes, Alkenes, and Alkynes. Molecular weight ↑ : London dispersion forces ↑ : bp ↑ More soluble in water than alkanes (Molecular weight ↑ : solubility ↓). C-O: (3.5 – 2.5 = 1.0) O-H : (3.5 – 2.1 = 1.4) polar nonpolar OH

Oxidation of 1° Alcohols In the oxidation [O] of a primary alcohol 1, one H is removed from the –OH group and another H from the C bonded to the –OH. primary alcohol aldehyde OH O │ ║ CH3─C─H CH3─C─H + H2O │ H ethanol ethanal [O] K2Cr2O7 H2SO4

Oxidation of 2° Alcohols The oxidation of 2 alcohols is similar to 1°, except that a ketone is formed. secondary alcohol ketone OH O │ ║ CH3─C─CH3 CH3─C─CH3 + H2O │ H 2-propanol 2-propanone [O] K2Cr2O7 H2SO4

Oxidation of 3° Alcohols Tertiary 3 alcohols cannot be oxidized. Tertiary alcohol no reaction OH │ CH3─C─CH3 no product CH3 no H on the C-OH to oxidize 2-methylpropan-2-ol [O] K2Cr2O7 H2SO4