Basic Organic Nomenclature

An Introduction

Dave Woodcock,
Associate Professor Emeritus UBC (Okanagan)
©1996,2000, 2008

5. Functional Groups
with Suffix or Prefix

I. Introduction

Index


The remaining functional groups to be covered in this tutorial have both a suffix and a prefix available for using in compound names.

This occurs because it is more convenient to string together a number of different functional groups using prefixes than using suffixes. So as a rule only one suffix is allowed.

As with everything there is an exception to the general rule: the C,C double bond suffix (en) and the C,C triple bond suffix (yn) can be used in addition to other suffixes.

To decide which of the remaining functional groups is expressed as a suffix rather than as a prefix, the functional groups are put into a priority order which to some extent follows oxidation number. However it is probably best to keep the table at hand and familiarize yourself with the actual order by rote.

Following is a table giving both suffix and prefix for the functional groups included in the tutorial (plus a few others), and the priority order.


Table of functional group names listed in ascending order of priority.

When more than one of the following functional groups is present in a molecule, the one lowest down the table has highest priority and uses the suffix, the other (or others) use(s) the prefix.

* - in this
tutorial
FormulaSuffixPrefix
*-amineamino
--thiolmercapto
*-olhydroxy
--thionethioxo
*-oneoxo
*-aloxo
*-nitrilecyano **
*-amide-
*-anoyl halide-
--sulfonic acidsulfo
*-oic acidcarboxy **
*-oate-

** Note: these two prefixes include the carbon of the functional group in the name. When counting carbons, don't forget to omit this one in the longest chain count!


Introductory Examples Using the Above Order of Priority

StructureIUPAC NameNotesModel
propan-1-ol 1 function
propan-1-amine 1 function
3-aminopropan-1-ol -ol has higher
preference
hydroxypropanone -one has higher
preference
propanoic acid OH and =O on same
carbon :
1 function
Self Assignment Questions
Review Alkenes.

Next page : Alkanamines.

Index


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