ACD/Name (Chemist Version) offers a standardized set of features for quick and simple generation of IUPAC names, and structures from names. It is a streamlined version of our popular ACD/Name software.
View a full description and pricing on our web store.
12.1 - If the compound is purely acyclic, the principal chain is chosen as parent for nomenclature by the methods given in Subsection C-0.13 and is named according to the Rules 1.1, 3.1, 3.2, and 3.3 of Section A.
12.2 - If the principal group occurs only in a chain which carries a cyclic substituent, the compound is named as an aliphatic compound into which the cyclic component is substituted, by means of a radical prefix. It is not necessary that the chain bearing the cyclic substituent shall be the longest chain.Example to Rule C-12.1
Principal group: -one Principal chain: Hexane Principal chain including principal group: 2-Hexanone Subtractive modification: 3-Hexen-2-one Prefixes: Chloro- Hydroxy- Methyl- Together with later rules this leads to the name: 3-Chloro-6-hydroxy-5-methyl-3-hexen-2-one
12.3 - If the principal group occurs in two or more carbon chains that are not attached directly to one another (that is, do not together form a branched chain but are separated by, for instance, a ring or hetero atom), then that chain is chosen as parent for nomenclature which carries the largest number of the principal group; if the numbers of these groups in two or more chains are the same, choice is made by the principles for selection of the principal chain (see Subsection C-0.13); if this does not effect a choice, the compound is named as an assembly of identical units (see Subsection C-0.7).Example to Rule C-12.2
Principal group: -oic acid Principal chain: Hexane Principal chain including principal group: Hexanoic acid Subtractive modification: 3-Hexenoic acid Prefixes: Chloro- Cyclohexyl- Hydroxy- Methyl- Together with later rules this leads to the name: 3-Chloro-5-cyclohexyl-6-hydroxy-5-methyl-3-hexenoic acid
12.4 - If the principal group occurs only in one cyclic system, that system forms the parent for nomenclature and is named according to the rules of Sections A and B.Example to Rule C-12.3
Principal group: -ol Principal chain, i.e., that carrying two OH: Ethanediol Prefix: p-(3-Hydroxypropyl)phenyl Together with later rules this leads to the name: 1-[p-(3-Hydroxypropyl)phenyl]-1,2-ethanediol
12.5 - If the principal group occurs in more than one cyclic system, that system is chosen as parent for nomenclature which carries the largest number of the principal group; if the numbers in two or more systems are the same, the senior ring system is chosen as parent according to the rules for seniority of ring systems in Subsection C-0.14; if these rules do not effect a choice, the substance is named as an assembly of identical units (see Subsection C-0.7).Example to Rule C-12.4
Principal group: -ol Parent: Cyclohexane Prefix: Ethyl- Together with later rules this leads to the name: 2-Ethyl-1-cyclohexanol
12.6 - If the principal group occurs both in a chain and in a cyclic system, the parent for nomenclature is that portion in which the principal group occurs in largest number; if the numbers are the same in two or more portions, that portion is chosen as parent for nomenclature which is considered to be the most important (for general considerations see Rule A-61) or is the senior (see Subsection C-0.14).Examples to Rule C-12.5
Principal group: -carboxylic acid Senior ring system for parent: Fluorene Name of parent including principal group: Fluorene-2-carboxylic acid Prefixes: Phenyl- Carboxy- Together with later rules this leads to the name: 6-(p-Carboxyphenyl)fluorene-2-carboxylic acid
12.7 - When a substituent is itself substituted, all the subsidiary substituents are named as prefixes. The substituent bearing the subsidiary substituents is regarded as a "parent radical" (analogous to a parent compound). The nomenclature of the whole substituent is subject to all the procedures adopted for compounds (for example, choice of principal chain) with two exemptions, namely (a) that no suffix is used and (b) that the point of attachment of the radial bears the lowest permissible number which for a chain must be 1 (see Rules A-1.2, A-2.25, and A-3.5).Examples to Rule C-12.6
Principal group: -ol Component carrying largest
number of principal groups:Name of parent including suffix: Pentanediol Substituent to be named as prefix: 4-Hydroxycyclohexyl Together with later rules this leads to the name: 1-(4-Hydroxycyclohexyl)-1,5-pentanediol Principal group: -one Component carrying largest
number of principal groups:1,2-Cyclopentanedione Substituent to be named as prefix: 2-Oxobutyl Together with later rules this leads to the name: 4-(2-Oxobutyl)-1,2-cyclopentanedione Principal group: -al Parent (Rule A-61.4): chain
Nonane Parent including suffix: Nonanal Substituent to be named as prefix: 4-Formylcyclohexyl Together with later rules this leads to the name: 9-(4-Formylcyclohexyl)nonanal
See Recommendations'93 R-4Example to Rule C-12.7
Principal group: -carboxylic acid Parent (Rule C-12.4) Cyclohexane Substituent to be named as prefix: Parent substituent chain: Hexyl- Subsidiary prefixes: Chloro- Oxo- name composed of:
Methyl- Hydroxy- giving Hydroxymethyl- Other substituent in cyclohexane ring: Chloro- Together with later rules this gives the name: 4,5-Dichloro-2-[4-chloro-2-(hydroxymethyl)-5-oxohexyl]-1-cyclohexanecarboxylic acid
Published with permission of the IUPAC by Advanced Chemistry Development, Inc., www.acdlabs.com, +1(416)368-3435 tel, +1(416)368-5596 fax. For comments or suggestions please contact webmaster@acdlabs.com
