Basic Organic Nomenclature

An Introduction

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

5. Functional Groups
with Suffix or Prefix

VII Alkanoic Acids
(carboxylic acids)


Atomic grouping
Suffix-oic acid (two words)
Prefixcarboxy (includes the carbon)
Position in chainonly at
end of chain
General formula CnH2nO2
Common family name carboxylic acids


  • Since the suffix (-oic acid) has an initial vowel, the terminal -e of the alkane name is dropped before the suffix is added.

  • For the first time the IUPAC name consists of two words, there being a space before the word 'acid'.

  • The carbonyl group in the alkanoic acid family is always at the end of a carbon chain and as such is always position 1. As with the alkanals and alkanamides, the locant (1) is omitted.

    pentanoic acid, NOT pentan-1-oic acid.

Examples :

StructureIUPAC NameModel
methanoic acid
(aka formic acid)
ethanoic acid
(aka acetic acid)
propanoic acid
octanoic acid
(Z)-hex-2-enoic acid
6-methylheptanoic acid
3-chloropentanoic acid
hexanedioic acid
6-hydroxy-4-oxononanoic acid

Self Assignment Questions
Review Alkanamides

Next page : Alkanoates (Esters).


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