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New IUPAC Organic Nomenclature and ACD/Name

NOTE: The updated IUPAC Rules from 2013 have been implemented in ACD/Name v2015. The full text of these rules is currently only available in the print version1 due to copyright infringements. When permitted, we will include the text of these rules in our ACD/Name software.

In December 2013 the new and long awaited Nomenclature of Organic Chemistry IUPAC Recommendations and Preferred Names was published. This major organic nomenclature publication is an answer to the rapid development of chemistry and appearance of new classes of chemicals we have seen over the past 20 years. The growing complexity of chemical substances greatly increases the reliance on nomenclature software among chemists, which in turn strongly demands a set of unambiguous nomenclature rules introduced by new recommendations. We at ACD/Labs welcome this change, as our mandate for the past 20 years has been to only generate single and correct chemical names for input structures.

ACD/Labs is proud of our participation in the development of new organic nomenclature recommendations both via our long membership in the corresponding IUPAC bodies and our contribution of the results of our work in the area of nomenclature. We continue to strive to update our ACD/Name software to support these new recommendations.

What are the changes to the IUPAC rules?

There are a variety of changes and new recommendations in the 2013 release of the IUPAC Recommendations on Nomenclature. The most important change is the concept of "Preferred IUPAC Name" (PIN), established by a hierarchical order of criteria allowing the derivation of a unique systematic name intended for registrations, patents, regulations, etc.

Additionally this publication includes nomenclature principles developed for more complex substances and new classes of compounds such as fullerenes and cyclophanes.

When did they come into effect?

The latest version of the IUPAC Recommendations on Nomenclature (Blue Book) was published in December 2013 by the Royal Society of Chemistry (ISBN: 978-0-85404-182-4,

Are the old names wrong?

It is important to note that any name other than a "preferred IUPAC name" (PIN) is still acceptable as a "general IUPAC name" as long as it is unambiguous and follows the principles of the IUPAC recommendations.

Is ACD/Labs nomenclature software, ACD/Name, compliant with the new rules?

ACD/Name already follows many of the nomenclature principles introduced in the latest recommendations. Due to our direct involvement in the work of the IUPAC committee, we had been involved in many of the discussions around the preferred naming protocols. Based on this knowledge, we have been implementing some changes since the first draft publication in 2004. We continue to update our software with the PIN recommendations which will be available with the release of ACD/Name version 2015.

Will all new principles be implemented in the next release of ACD/Name?

No. Since the early 2004 draft and even later 2010 version of the recommendations, a significant number of changes were introduced in preparation of the official publication. Thus, the implementation of all new principles could not start until the official release. Additionally, some new principles require significant development of new advanced algorithms. We expect implementation of all major changes in the next version of ACD/Name and a clear indication of any possible deviations from PINs.

What about names in other languages?

The translation of the latest organic nomenclature recommendations to other languages will gradually appear; allowing those users to follow the new principles in non-English names. The algorithmic names generated by ACD/Name in ten languages under the new principles will be implemented in the next version release for all currently supported languages.


1. Favre, Henri A. and Powell, Warren H. Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Name 2013. Cambridge, UK: The Royal Society of Chemistry, 2013. ISBN 978-0-85404-182-4.