Basic IUPAC Organic Nomenclature

Acid Anhydrides

Nomenclature	Formula	3D structure
Functional class name = alkanoic anhydride Substituent suffix = -oic anhydride

• As the name implies, acid anyhydrides are derivatives of carboxylic acids.
• In principle, they can be symmetric (where the two R groups are identical) or asymmetric (where the two R groups are different).
• Symmetric anhydrides are the most common, they are named as alkanoic anhydrides
• Asymmetric anhydrides are name in a similar fashion listing the alkyl groups in alphabetical order.
• Cyclic anhydrides derived from dicarboxylic acids are name as -dioic anhydrides.
  

Functional group is an acid anhydride therefore suffix = -oic anhydride Hydrocarbon structure is an alkane therefore -an- The longest continuous chain is C2 therefore root = eth ethanoic anhydride	CH3C(=O)OC(=O)CH3
Functional group is an acid anhydride therefore suffix = -oic anhydride Hydrocarbon structure is an alkane therefore -an- The longest continuous chain is C4 therefore root = but The other group is C3 = prop butanoic propanoic anhydride
Functional group is a cyclic acid anhydride therefore suffix = -dioic anhydride Hydrocarbon structure is an alkane therefore -an- The longest continuous chain is C5 therefore root = pent pentandioic anhydride

© Dr. Ian Hunt, 2005, Department of Chemistry, University of Calgary