(a) All heterocycles are senior to all carbocycles.
(b) For heterocycles the criteria based on the nature and position of the hetero atoms set out in Rule B-3.1.
Example to Rule C-14.11(a)
(c) Largest number of rings.
Examples to Rule C-14.11(b)
See Rule B-3.1, such as:
(d) Largest individual ring at first point of difference.
Example to Rule C-14.11(c)
(e) Largest number of atoms in common among rings.
Examples to Rule C-14.11(d)
Note: Rings joined by a link (single or double) are included in this choice only when identical and named by the bi-, ter-, quater-, etc., system (see Rule A-54.1).
Examples to Rule C-14.11(e)
(f) Lowest letters (a, b, etc., see Rule A-21.5) in the expression for ring junctions.
(g) Lowest numbers at the first point of difference in the expression for ring junctions. (See Rules: A-21.5, for ortho-fusion and ortho-peri-fusion; A-32 for tricyclo, etc., systems; A-41, A-42, B-10, and B-11 for spirans; A-52 for assemblies of identical units.)
Example to Rule C-14.11(f)
(h) Lowest state of hydrogenation.
Examples to Rule C-14.11(g)
(i) Lowest locant for indicated hydrogen.
Example to Rule C-14.11(h)
(k) Lowest locant for an attached group expressed as suffix.
Example to Rule C-14.11(j)
() Maximum number of substituents cited as prefixes.
Example to Rule C-14.11(k)
(l) Lowest locant for substituents named as prefixes, hydro prefixes, -ene, and -yne, all considered together in one series in ascending numerical order independently of their nature.
(m) Lowest locant for that substituent named as prefix which is cited first in the name (see Subsection C-0.16)
Examples to Rule C-14.11(l)
Note: Hydro and dehydro prefixes, if treated as detachable (see Rule C-16.11), are considered along with prefixes for substituents when this criterion is applied.
Example to Rule C-14.11(m)
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 email@example.com