Alcohols and Phenols

• Alcohols (R-OH)


  Organic compounds that contain an -OH group attached to a saturated carbon atom

  
• Classification of Alcohol


  • Monohydric alcohols (presence of 1 -OH group)
  • Dihydric alcohols (Presence of 2 -OH groups)
  • Trihydric alcohols (Presence of 3-OH groups)

  
• Base of Substituent


  • Alkyl alcohol
  • Vinylic alcohol
  • Allylic alcohol
  • Benzylic alcohol
  • Phenol

  
• Primary alcohol


  Carbon atom attached to hydroxyl is attached to a single alkyl group

  
• Secondary alcohol


  2 carbon atoms where hydroxyl is attached to

  
• Tertiary alcohol


  3 carbon atoms where hydroxyl is attached to

  
• Vinylic alcohol


  Vinyl - removal of one hydrogen in Ethyl, Attached an OH group, Generally unstable in nature, Isolated forms - polymer derivatives; esters; ether

  
• Pyrolytic elimination


  1. Elimination of H2O from ethylene glycol (C2H6O2)

  2. Produce vinylic ROH

  3. No need to attached OH group

  
• Vinylic Alcohol


  • Primary Vinylic Alcohol
  • Secondary Vinylic Alcohol

  
• Allylic Alcohol


  Removal of one hydrogen, Open attachment attached to OH = Allylic Alcohol
• Benzylic Alcohol


  Aromatic alcohol, OH attached to a methyl group that is attached to a benzene ring

  
• Phenol Compounds


  Carbolic acid, Alcohols are less acidic than phenol, Alcohol is attached to a saturated carbon, Resonance - conjugated pi system - more acidic
• Nomenclature of Alcohol


  1. Name all carbon atoms as a single alkyl group

  2. Add the word alcohol, separating the words with a space

  
• IUPAC System


  • Name the longest carbon chain containing the -OH group
  • The -e of alkane is dropped and replaced with -ol
  • Number the chain starting at the end closest to the -OH group
  • Name and locate other substituent
  • The locant indicating the -OH group can be placed before the parent or before the suffix -ol
  • If the -OH group is attached to a chiral center, the absolute configuration needs to be included at the beginning of the name
  • In the presence of a double bond, the E and Z configuration would be addressed when applicable
  • In alcohols where -OH group is attached to a carbon atom in a ring, the functional group is assumed to be at carbon 1
• One Hydroxyl Group


  • methylhexane - 3 - ol
  • 2 - ethylbutan - 1 - ol
  • 3, 4 - dimethylcyclohexanol

  
• More than one Hydroxyl group


  • 1, 2 - ethan -diol (ethylene glycol)
  • 1, 2 - propan - diol
  • 1, 2, 3 - propan - triol (glycerol)