PhI-3. Numbering of Phane Parent Hydrides

PhI-3. Numbering of Phane Parent Hydrides
PhI-3.1. Numbering of Phane Parent Skeletons and Amplificants
References for this section

The following rules are used for numbering phane parent hydrides. These rules are hierarchical, i.e., each particular rule is applied only to alternatives not eliminated by preceding rules.

PhI-3.1. Numbering of Phane Parent Skeletons and Amplificants

PhI-3.1.1. The numbering of a phane parent skeleton is first determined by the rules governing the appropriate skeletal class to which it belongs (see PhI-2.1). When, because of skeletal symmetry, these rules leave alternatives, the numbering that gives the lowest set of locants for the superatoms is preferred. The lowest set of locants (refs. 1b, 2b) is the one that has the lowest numerical value at the first point of difference, when the sets are compared term by term in order of increasing numerical value.

PhI-3.1.2. Numbering of an amplificant is determined primarily by the numbering rules that apply to the parent hydride from which the amplificant is derived. When there is a choice, the established procedure for lowest locants is applied . The lowest locant set (refs. 1b, 2b) is the one that has the lowest numerical value at the first point of difference when the sets are compared term by term in order of increasing numerical value.

These two rules are exemplified by the following examples.

Example 1.

1(4)-pyrimidina-3,6(5,2),9(3)-tripyridinanonaphane

not 9(4)-pyrimidina-1(3),4,7(2,5)-tripyridinanonaphane

(See PhI-2.1.1 and PhI-3.1.1; the superatom locant set of the correct name, "1,3,6,9", is lower than "1,4,7,9".)

not 1(4)-pyrimidina-3,6(2,5),9(3)-tripyridinanonaphane

[See PhI-2.3.2.2; the first locant of the attachment locant set "(2,5)" is not the locant adjacent to the lower locant of the simplified skeleton.]

not 1(4)-pyrimidina-3(5,2),6(5,2),9(3)-tripyridinanonaphane

[See PhI-2.3.2.1; the identical attachment locant sets "(5,2)" must be contracted to "3,6(5,2)".]

not 1(4)-pyrimidina-3,6(3,6),9(3)-tripyridinanonaphane

[See PhI-3.1.2; the attachment locant set "(5,2)" of the pyridine amplificant in the correct name, written in the ascending numerical order "(2,5)" for comparison, is lower than the set "(3,6)".]

Example 2.

3(5,2)-pyridina-1(3,1)-piperidina-6(3,1)-naphthalenacyclononaphane

not 7(5,2)-pyridina-5(1,3)-piperidina-1(1,3)-naphthalenacyclononaphane

(See PhI-2.1.2 and PhI-3.1.1; the superatom locant set of the correct name, "1,3,6", is lower than the locant set "1,5,7".)

not 3(2,5)-pyridina-1(1,3)-piperidina-6(1,3)-naphthalenacyclononaphane

[See PhI-2.3.2.2; the first locant of each of the attachment locant sets "(2,5)", "(1,3)", and "(1,3)" for the pyridine, piperidine, and naphthalene amplificants, respectively, is not the locant adjacent to the lower locant of the phane parent skeleton.]

Example 3.

17(5,2)-pyridina-5(4,2)-furana-13(4,2)-thiophenabicyclo[8.5.3]octadecaphane

not 17(2,5)-pyridina-11(4,2)-furana-4(4,2)-thiophenabicyclo[8.5.3]octadecaphane

not 3(5,2)-pyridina-14(4,2)-furana-8(4,2)-thiophenabicyclo[8.5.3]octadecaphane

(See PhI-2.1.3; the superatom locants in the incorrect names, "4,11,17" and "3,8,14", are not allowed by the numbering rules for the bicyclic system.)

PhI-3.1.3. Amplification of symmetrical simplified phane skeletons with at least two superatoms representing different amplificants results in the loss of symmetry and creates numbering alternatives. In such cases, the lower available superatom locant is assigned to an amplificant that appears earlier in the seniority of rings and ring systems (see PhI-2.2.3). The application of this procedure may require a sequence of steps. First, the lowest available superatom locant(s) is (are) assigned to the amplificants appearing first in the seniority order. Then, the same procedure is applied successively to assign remaining superatom locants to the rest of the amplificants.

Example 4.

1(5,8)-quinolina-4(2,5)-pyridina-7(4,1)-phenanthrenacyclononaphane

not 1(8,5)-quinolina-7(5,2)-pyridina-4(1,4)-phenanthrenacyclononaphane

[The senior amplificant is quinoline (see PhI-2.2.3) and must receive the lowest superatom locant, "1"; the pyridine amplificant is second in seniority (see PhI-2.2.3) and therefore must be given the second lowest superatom locant, "4".]

not 1(5,8)-quinolina-4(2,5)-pyridina-7(1,4)-phenanthrenacyclononaphane

[See PhI-2.3.2.2; the attachment locants of the phenanthrene amplificant, "(1,4)" are not correctly cited; the first locant of the attachment locant set is not the locant adjacent to the lower locant of the phane parent skeleton, "6".]

Example 5.

2(5,8)-quinolina-9(2,5)-pyridina-5(4,2),12(2,4)-difuranaspiro[6.6]tridecaphane

not 2(5,8)-quinolina-12(5,2)-pyridina-5,9(4,2)-difuranaspiro[6.6]tridecaphane

[The senior amplificant is quinoline (see PhI-2.2.3) and must be given the lowest superatom locant,"2"; the pyridine amplificant is second in seniority (see PhI-2.2.3) and must be assigned the next available lowest superatom locant, "9"; therefore the furan amplificants have the superatom locants "5" and "12".]

PhI-3.1.4. When, because of symmetry, PhI-3.1.2 leaves a choice, an amplificant is numbered in such a way that the lower attachment locant is adjacent to the lower locant of the phane parent skeleton (see also PhI-2.3.2.2).

Example 6.

1(2,7)-naphthalena-4(1,4)-benzenacycloheptaphane

[See PhI-2.1.2 and PhI-3.1.1; the lowest locant set for the superatoms in the phane parent skeleton is "1,4"; the senior amplificant, naphthalene (see PhI-2.2.3), must be assigned the superatom locant "1".]

not 1(2,7)-naphthalena-4(4,1)-benzenacycloheptaphane

not 1(7,2)-naphthalena-4(4,1)-benzenacycloheptaphane

(The correct citation for the attachment locant sets, "1,4" for benzene and "2,7" for naphthalene, places the lower attachment locant adjacent to the lower locant of the phane skeleton.)

Example 7.

1(4,2,6),10(2,4,6)-dipyridina-12(1,3)-benzenabicyclo[8.6.0]hexadecaphane

[The attachment locant sets of both pyridine amplificants are "(2,4,6)". However, the attachment locant sets of each amplificant must follow PhI-2.3.2.2, i.e., the lower locant of each attachment locant set must be next to the lowest possible locant of the phane skeleton. The attachment locant "4" in each pyridine amplificant is invariant. Locant "2" of amplificant "1" must be adjacent to phane skeletal locant "10" (not "16") and locant "2" of amplificant "10" must be adjacent to phane skeletal locant "1" (not "11").]

not 1(4,2,6),10(2,4,6)-dipyridina-15(1,3)-benzenabicyclo[8.6.0]hexadecaphane

(See PhI-2.1.3 and PhI-3.1.1; the superatom locant set in the correct name, "1,10,12", is lower than "1,10,15".)

not 1,10(2,4,6)-dipyridina-12(1,3)-benzenabicyclo[8.6.0]hexadecaphane

(See PhI-2.3.2.1; since the attachment locant sets of the two pyridine amplificants are not identical, they must be cited separately.)

(1) International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, R. Panico, W. H. Powell and Jean-Claude Richer (Senior Editor), Blackwell Scientific Publications, Oxford, 1993, 190 pp. (a) R-1.2.2.1, p. 23; R-2.3.3.2, p. 43; R-5.5.4.3, p. 95. (b) R-0.2.4.2, p. 17. (c) R-2.4.2.1, especially footnote 29, p. 49. (d) R-2.4.3, p. 51. (e) R-2.4.2, pp. 49-51. (f) R-2.4.3.1, pp. 51-2. (g) R-2.4.3.2, p. 52. (h) R-0.1.8, p. 10. (i) R-2.3.1.2, p. 39; R-2.3.3 (in part), pp. 40-4; R-2.4.1, pp. 44-9. (j) R-2.4.1.2, p. 46. (k) R-2.3.1.1, p. 39; R-2.3.3 (in part), pp. 40-4. (m) R-9.3, p.182. (n) R-2.3.3.2, p. 43. (o) R-2.4.2, pp. 49-51.

(2) International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, 1979 Edition, J. Rigaudy and S. P. Klesney eds., Pergamon Press, Oxford 1979, 559 pp. (a) B-4, pp. 68-70; C-0.6, pp. 123-7; D-1.6, pp. 334-6; D-5.17, p. 388; D-6.71, pp. 419-20. (b) A-2.6, p. 10, footnote; C-13.11(e), p. 99, footnote; D-4.14, p. 374, footnote. (c) A-31.1, p. 31, especially its footnote. (d) Spiro hydrocarbons, p. 37, especially its footnote. (e) A-31.1 and A-31.2, p. 31; A-32, pp. 32-4. (f) A-41.1 and A-41.2, p. 38. (g) A-41.6, p. 39. (h) C-16.11, p. 108. (i) A-11.3, pp. 16-17 (benzene); A-21 and A-22, pp. 20-7; B-2 (in part) and B-3, pp. 55-68. (j) A-34, pp. 35-7; B-15 (in part), pp. 75-6. (k) A-11.1, p. 16; B-2.12 (in part), pp. 62-3; D-4.21, p. 375; D-4.51 (in part), pp. 378-9. (m) Appendix, Table I, pp. 459-60. (n) B-14 (in part), p. 75. (o) B-10.1, p. 72.

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