Extension and Revision of the Nomenclature for Spiro Compounds
(IUPAC Recommendations 1999)

SP-3 to SP-5

Continued from SP-2

Contents of Section

SP-3 Three identical components spiro-fused together
SP-4 Monospiro compounds with different components at least one of which is polycyclic
SP-5 Unbranched polyspiro compounds with at least two different components and at least one of which is polycyclic
References for this section


SP-3 Three identical components spiro-fused together

SP-3.1 Dispiro compounds where each component is identical are named by placing the prefix dispiroter- before the name of the component ring system in square brackets. Locants required to define the component ring systems are placed in square brackets. The middle component is numbered with primed locants and the numbers of the third component are double primed. The spiro atoms are indicated in front of the name by two pairs of locants separated by a colon. Indicated hydrogen is cited in front of these locants if needed.

Examples:


3,3':6',6"-dispiroter[bicyclo[3.1.0]hexane]


However 3,6λ5,9λ5,12-tetraazadispiro[5.2.5.2]hexdecane-6,9-bis(ylium)
(see SP-8 for naming of compounds with ionic spiro atoms)

Note This ring system has been called N,N"-dispirotripiperazinium.

SP-3.2 If there is a choice of locants the lowest set of locants for all spiro atoms is selected when compared as a set in ascending order and, if still undecided, in citation order. If a choice still remains the criteria of SP-1.8 apply. Indicated hydrogen is considered between SP-1.8.5 and SP-1.8.6.

Examples:


1H,1'H,1"H,3'H-2,2':7',2"-dispiroter[naphthalene]


1"H,2H,5'H,7'H-1,6':1',2"-dispiroter[naphthalene]
not 1'H,1"H,2H,3'H-1,2':5',2"-dispiroter[naphthalene]
nor 1H,2"H,5'H,7'H-2,1':6',1"-dispiroter[naphthalene]
(1,1',2",6' is lower than 1,2',2",5' or 1',1",2,6')


1'H,1"H,2H,8'H-1,2':7',2"-dispiroter[naphthalen]-1'-one error details

SP-3.3 Ring systems composed of three identical components with only one spiro atom are named by placing the prefix spiroter- before the name of the component ring system in square brackets. The three spiro locants are indicated in front of the name.

Example:


6,2',2"-spiroter[[1,3,2]benzodioxathiole] (see SP-7 for the use of λ)

SP-4 Monospiro compounds with different components at least one of which is polycyclic

SP-4.1 Monospiro compounds with different components at least one of which is polycyclic are named by placing the component names within square brackets in alphabetical order and prefixing this with spiro. The position of the spiro atom is denoted by the appropriate locants separated by a comma placed between the two component names. Locants of the second component are primed and any locants needed to name this component ring system are not primed but placed in square brackets. Indicated hydrogen is cited if necessary in front of the complete name.

Examples:


spiro[cyclopentane-1,1'-indene]


spiro[fluorene-9,2'-[3]thiabicyclo[2.2.2]oct[5]ene]
CAS index name spiro[9H-fluorene-9,3'-[2]thiabicyclo[2.2.2]oct[5]ene]


1'H-spiro[imidazolidine-4,2'-quinoxaline]


spiro[piperidine-4,9'-xanthene]


4',7'-dihydrospiro[1,3-dioxolane-2,2'-[4,7]epoxyindene]


3H-spiro[1-benzofuran-2,1'-cyclohex[2]ene]


spiro[bicyclo[2.2.1]hept-5-ene-2,1'-[2,12]dioxacyclododec[6]ene]

SP-4.2 If alphabetical order is inadequate to decide between two names ring seniority principles based on lower italic fusion letters and numbers, heteroatom locants and von Baeyer cypher are used (see C-14.11, ref 5).

Examples:


spiro[1,2-benzodithiole-3,2'-[1,3]benzodithiole] error details
(1,2 before 1,3)


spiro[3,1-benzoxazine-7,6'-[2,3]benzoxazine]
(1,3 before 2,3)

SP-4.3 Ring systems composed of three components, at least two of which are different, and with only one spiro atom are named by placing the prefix spiro in front of the names of the components in alphabetical order with the appropriate spiro locants. The multiplicative prefix bis is used for identical components. With three different components the component cited in the middle of the name is enclosed in parentheses to highlight this unusual situation. (See SP-7 for the use of λ.)

Examples:


6-spiro[1,3,2-benzodioxathiole-2,2'-([1,2,3]benzoxadithiol)-2,5"-dibenzo[b,d]thiophene]


6-spiro[bis([1,3,2]benzodioxathiole)-2,2":2',2"-[1,2,3]benzoxadithiole] error details

SP-4.4 Ring systems spiro-fused to natural products may also be named in a similar way to SP- 4.1. Examples are steroids (rule 3S-10.3, ref 14) and carbohydrates (rule 2-Carb-35.3, ref 15).

SP-5 Unbranched polyspiro compounds with at least two different components and at least one of which is polycyclic

SP-5.1 Unbranched polyspiro compounds with at least two different components and at least one of which is polycyclic are named by placing each component name in order of occurrence in square brackets beginning with the terminal component earlier in alphabetical order, with a prefix to indicate the number of spiro atoms in front (dispiro-, trispiro-, etc.). Locants of the first cited component are unprimed, the next one is primed and so on. Locants which form part of the name of the second and later components are not primed but cited in square brackets. The positions of the spiro atoms are indicated by the appropriate pair of locants separated by a comma between each pair of component ring system names. Indicated hydrogen, if necessary, is cited in front of the complete name. If there is a choice of names the first cited is the one earlier in alphabetical order for the second (then third etc.) component. Multiplicative prefixes are not used with dispiro systems having identical terminal components.

Examples:


dispiro[fluorene-9,1'-cyclohex[2]ene-4',1"-indene]
not dispiro[indene-1,1'-cyclohex[2]ene-4',9"-fluorene] [fluorene before indene]


2"H,4"H-trispiro[cyclohexane-1,1'-cyclopentane-3',3"-cyclopenta[b]pyran-6",1'''-cyclohexane]
not 2'H,4'H-trispiro[cyclohexane-1,6'-cyclopenta[b]pyran-3',1"-yclopentane-3",1'''-cyclohexane]
[cyclopentane before cyclopenta[b]pyran]
Note that the 2"H is not strictly necessary here.

SP-5.2 If there is a choice of locants the criteria ofSP-3.2 and then SP-1.8 apply until a decision is made.

Examples:


1'H-dispiro[1,3-benzoxathiole-2,10'-[1,4]ethanonaphthalene-5',2"-[1,3]dioxolane]
not 4'H-dispiro[1,3-benzoxathiole-2,9'-[1,4]ethanonaphthalene-8',2"-[1,3]dioxolane] (2,2",5',10' is lower than 2,2",8',9')


dispiro[1,3-dioxolane-2,3'-bicyclo[3.2.1]octane-6',2"-[1,3]dioxolane]
not dispiro[1,3-dioxolane-2,6'-bicyclo[3.2.1]octane-3',2"-[1,3]dioxolane] [2,3',6',2" is lower than 2,6',3',2"]
nor dispiro[bicyclo[3.2.1]octane-3,2':6,2"-bis([1,3]dioxolane)]

Note This is the traditional method of naming such systems but the use of a multiplicative prefix as in the third name of the above example is more concise and unambiguous.


References for this Section

5. IUPAC, Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F and H, 1979 edition, Pergamon Press, Oxford, 1979.

14. IUPAC-IUB, Nomenclature of steroids, recommendations 1989, Eur. J. Biochem. 186, 429-458 (1989); Pure Appl. Chem. 61, 1783-1822 (1989) and in Dictionary of Steroids (eds R.A. Hill, D.N. Kirk, H.L.J. Makin and G.M. Murphy) Chapman and Hall, London, 1991, pp xxx-lix; IUBMB, Biochemical Nomenclature and Related Documents, second edition, Portland Press, London, 1992, pp. 192-221.

15. IUPAC-IUBMB, Nomenclature of Carbohydrates, Recommendations 1996, Adv. Carbohydr. Chem. Biochem. 1997, 52, 43-177; Carbohydr. Res. 1997, 297, 1-90; J. Carbohydr. Chem. 1997, 16, 1191-1280; Pure Appl. Chem. 68, 1919-2008 (1996).


Continued with SP-6 and SP-7
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