ALCOHOLS

• Alcohols


  Compounds which contain one or more hydroxyl (-OH) groups directly attached to a carbon chain
• Alcohols in the free-form are not a common occurrence in nature; they are found mainly in the essential or volatile oils obtained from flowers, leaves, and stems of the plants
• Oxidation of Alcohol


  1. Alcohols undergo oxidation in the presence of an oxidizing agent to produce aldehydes and ketones

  2. Aldehydes and ketones upon further oxidation give carboxylic acids
• Dehydration of Alcohol


  1. Upon treatment with protic acids, alcohols undergo dehydration (removal of a molecule of water) to form alkenes

  2. Dehydration of alcohols with conc. H2SO4 at different temperatures yields different products
• Ease of dehydration of alcohols

  1° ROH < 2° ROH < 3° ROH
• Reaction with metals


  1. Na + RO-H → RO-Na + 1/2 H2

  2. 3RO-H + Al → (RO)3Al + 3/2 H2
• Reaction with carboxylic acid (Esterification)


  1. OH + R'-COOH → R'-COOR + H2O
• Formation of halides


  1. R-OH + PX3 → R-X + H3PO3

  2. R-OH + SOCl2 → R-Cl + SO2 + HCl

  3. 6R-OH + 2P + 3I2 → 6R-I + 2H3PO3
• Hydrolysis of Halides


  1. X + KOH → R-OH + KX
• Hydration of Alkenes


  1. Direct hydration: CH2=CH2 + H2O → CH3CH2OH

  2. Indirect hydration: CH2=CH2 + H2SO4 → CH3CH2OSO2OH → CH3CH2OH
• Grignard Synthesis


  1. R-MgBr + H-C=O → R-C-OMgBr → R-C-OH

  2. R-MgX + R'C=O → R-C-OMgX → R-C-OH
• Uses of Alcohols


  • Alcoholic Drinks
  • Industrial methylated spirits
  • Use of ethanol as a fuel
  • Ethanol as a solvent
  • Methanol as a fuel
  • Methanol as an industrial feedstock