Synthetic routes

• Organic synthesis is the preparation of complex molecules from simple starting materials
• To go from an alkane to a haloalkane:

  • react alkane with halogen
  • UV to break the halogen molecule into radicals
• To go from alkene to alkane:

  • react with hydrogen
  • in the presence of a nickel catalyst
• To go from alkene to haloalkane:

  • react with hydrogen halide
  • room temp
• To go from alkene to alcohol:

  • react with water
  • in presence of phosphoric acid catalyst
• To go from alcohol to alkene:

  • heat the alcohol under reflux
  • in presence of acid catalyst e.g. sulfuric acid or phosphoric acid
  • this is dehydration.
• To go from halo alkane to alcohol:

  • react with NaOH(aq)
  • under reflux
• To go from alcohol to haloalkane:

  • react with a sodium halide and sulfuric acid
• To go from primary alcohol to carboxylic acid:

  • react with acidified potassium dichromate
  • heated under reflux
• To go from primary alcohol to aldehyde:

  • react with acidified potassium dichromate
  • distil
• To go from secondary alcohol to ketone:

  • react with acidified potassium dichromate
  • heat under reflux
• The term target molecule is used to describe the compound that the chemist is attempting to prepare by organic synthesis
• In a simple synthesis, the target molecule can be obtained by reacting a readily available starting material with a readily available reagent in a one-step reaction.

  In most cases, synthesis is not that straight forward
• To convert a starting molecule into the target molecule you need to:

  • identify the functional groups in your starting and target molecules
  • identify the intermediate that links the starting and target molecules
  • state the reagents and conditions for each step