Synthetic Routes (OCR AS Chemistry A)

Two-Stage Organic Synthetic Routes

• It is possible to make a large number of organic products from a few starting compounds and the necessary reagents and conditions

• Knowing how organic functional groups are related to each other is key to the synthesis of a given molecule

• The main functional groups you need to know are

  • Alkanes

  • Alkenes

  • Haloalkanes

  • Alcohols

  • Carbonyls (aldehydes & ketones)

  • Carboxylic acids

Aliphatic Reaction Pathways

• The key functional groups and their interconversions are summarised here:

The main reaction pathways at AS level

Designing a Reaction Pathway

• The given molecule is usually called the target molecule and chemists try to design a synthesis as efficiently as possible

• Designing a reaction pathway starts by drawing the structures of the target molecule and the starting molecule

• Determine if they have the same number of carbon atoms

  • If you need to lengthen the carbon chain you will need to put on a nitrile group by nucleophilic substitution

• Work out all the compounds that can be made from the starting molecule and all the molecules that can be made into the target molecule

  • Match the groups they have in common and work out the reagents and conditions needed