Basic Organic Nomenclature


The material in these tutorials are intended to aid in your understanding of basic organic nomenclature. The pages are subdivided into topics based on the different functional groups present in organic molecules. Each section consists of a brief introduction, including examples, and a number of interactive on-line quizzes to test your understanding of the material. As a student it is your responsibility to determine when you have a sufficient understanding of the material.

Organic nomenclature is based on the priority of the different functional groups in the molecule. If you are not familiar with the different functional groups you need to study them first.

These pages make use of a number of visual aids to display molecules. You will need a copy of the Chime plug-in from MDL Information Systems to view some of these structures. If you are not familiar with Chime check this short help page.


IUPAC Rules of Nomenclature

The International Union of Pure and Applied Chemists (IUPAC) has devised a system of rules which act as a guideline in naming organic molecules. A standardized system for naming organic compounds was needed due to the vast number of structures possible with hydrocarbons. Although the IUPAC system of nomenclature has been in place since the 1930's, there are a number of compounds which are still referred to by their common names. This complicates organic nomenclature to some degree as several names may be possible for any single compound.

Since every organic molecule contains carbon (and usually hydrogen) atoms, the names of these two elements do not appear in the name of the compound. Instead IUPAC uses the longest continuous chain of carbon atoms to determine the basic, or root name of the compound. The root name is then modified by the presence of different functional groups. The highest priority functional group modifies the suffix of the root name, while all other groups, or substituents, are added as prefixes to the root name.


The following list of functional groups will contain an introduction to the nomenclature of that functional group, including examples. At the end of each section is an on-line quiz designed to test your new knowledge of the subject.

All of the nomenclature online quizzes can be accessed through this link: Nomenclature Quizzes If you can not seem to get the correct answer, enter a "?" in the text box and you will get the correct answer returned.