Nomenclature of organic compounds

• Hydrocarbons can be classified as:

  • ALIPHATIC = carbon atoms are joined to each other in unbranched or branched chains, or non-aromatic rings
  • ALICYCLIC= carbon atoms are joined to each other in ring (cyclic) structures, with or without branches
  • AROMATIC = some or all of the carbon atoms are found in a benzene ring
• Benzene ring = six carbon atoms bonded in a ring with alternating c-c single and double bonds around the ring. (a hydrogen attached to each carbon ofc)
• Homologous series of aliphatic hydrocarbons:

  • alkanes: single c-c bonds
  • alkenes: at least one double c-c bond
  • alkynes: at least one triple c-c bond
• The stem of the name indicates the number of carbon atoms in the longest continuous chain in the molecule
• A prefix can be added before the stem often to indicate the presence of side chains or functional groups
• A suffix is added after the stem to indicate functional groups
• When naming alicyclic alkanes the prefix cyclo- in front of the stem is used to show that the carbon atoms are arranged in a ring structure
• Alkenes are named using the same rules as for alkanes, except the suffix is -ene. The position of the double bond in the chain must be stated for alkenes that have four or more carbon atoms
• The suffix of an alcohol is -ol
• The suffix of an aldehyde is -al. Aldehydes do not need numbers to show the position of the carbonyl (-CHO) group because it is always on position 1.
• Side chains are named in alphabetical order. E.g. 2-chloro-2-methylbutane