M5.2

• SN1 nucleophilic substitution


  The slow reaction which normally occurs
• Bordwell-Wellman test


  Also known as chromic acid test
• Oxidation of alcohols by chromic acid

  1. Primary alcohols to carboxylic acid

  2. Secondary alcohols to ketones

  3. Tertiary alcohols not oxidized
• Phenols


  Compounds containing hydroxyl group (OH) connected to an aromatic ring/benzene
• Phenols


  • Solubility in water is much lower than alcohols due to larger hydrocarbon
  • Boiling point is higher than corresponding aromatic hydrocarbons, haloarenes, aldehydes and ketones due to hydrogen bonding
  • React with aqueous alkalis whereas alcohols do not, so are more acidic than alcohols
• Bromine reaction with phenol

  Phenol in water converted to phenoxide ion, which is strongly activating, leading to tribromo-substitution
• Ferric chloride reaction with phenol

  Forms colored complex (oxidation reaction)
• MEDICINAL / PHARMACEUTICAL USE OF ALCOHOLS

  Isopropyl Alcohol (Antiseptic/Disinfectant)

  Ethyl Alcohol (Antiseptic/Disinfectant Solvent)

  Methanol (Solvent for analysis)

  Chlorocresol (Preservative)

  Eugenol (Antiseptic)
• MEDICINAL AGENTS WITH PHENOL SUBSTITUENTS

  Tetracycline (Antibiotic)

  Levodopa (Treatment of Parkinsonism)

  Epinephrine (Vasoconstrictor and cardiac stimulant)