SP-6 to SP-7

Contents of Section

SP-6 Branched polyspiro compounds with at least one polycyclic component
SP-7 Spiro systems containing atoms with non-standard valency
References for this section

When three or more components are spiro-fused to the same component the ring system is described as a branched spiro-fused ring system. Terminal components have only one spiro atom.

SP-6.1 If a central component is spiro-fused to three or more identical terminal components the central component is cited first and its locants are unprimed. The terminal components are cited with the appropriate multiplicative prefix (tris, tetrakis, etc.) and locants are primed, double primed etc. The spiro atoms are indicated by pairs of locants separated by colons. Indicated hydrogen is cited if necessary in front of the complete name.

Example:

trispiro[1,3,5-trithiane-2,2':4,2":6,2'''-tris(bicyclo[2.2.1]heptane)]

SP-6.2 If two or more different terminal components are spiro-fused to a central component the alphabetically first is quoted first with a multiplicative prefix if appropriate followed by the central component and then the remaining terminal components in alphabetical order.

Examples:

trispiro[adamantane-2,3'-[1,2,4,5,7,8]hexoxonane-6',1":9',1'''-bis(cyclohexane)](preferred name)
Alternative name
trispiro[bis(cyclohexane)-1,3":1',6"-[1,2,4,5,7,8]hexoxonane-9",2'''-triycyclo[3.3.1.1^3,7]decane]

trispiro[1,3-benzodioxole-2,1'-cyclohexane-2',2":4',2'''-bis([1,3]dioxolane)]

2λ⁶-dispiro[bis([1,3,2]benzodioxathiole)-2,1":2',1"-thiopyran-4",1'''-cyclopentane]

trispiro[cyclopentane-1,1'-cyclohexane-3',2"-imidazole-5',1'''-indene]

SP-6.3 If there is a choice of locants the criteria of SP-3.2 and then SP-1.8 apply.

Example:

1'λ⁴-trispiro[cyclopentane-1,5'-[1,4]dithiane-2',2"-indane-1',1'''-thiophene]
not 1'λ⁴-trispiro[cyclopentane-1,3'-[1,4]dithiane-6',2"-indane-1',1'''-thiophene]
nor 4'λ⁴-trispiro[cyclopentane-1,2'-[1,4]dithiane-5',2"-indane-4',1'''-thiophene]
(1,1',1''',2',2",5' is lower than 1,1',1''',2",3',6' or 1,1''',2',2",4',5')

SP-6.4 If additional components are spiro-fused to a branched polyspiro compound as described in SP-6.1 to SP-6.3 the following criteria are applied in order:

   (a) Any monocyclic ring components spiro-fused together are named (see SP-1) as a unit containing the maximum number of monocyclic ring components. This unit is used as a component for further spiro-fusion (see SP-5). To help indicate the composite nature of the name braces are used (instead of square brackets) after the initial polyspiro prefix to enclose components at least one of which is already spiro-fused.

   (b) If there is not a polyspiro system composed of monocyclic ring components or the system cannot be named by the normal spiro-fusion rules (see SP-2 to SP-6.1) the largest preferred spiro system is named and treated as a unit for further spiro-fusion. The priming of this unit is continued in the rest of the name.

SP-6.4.1 After identification of the spiro-fused components these, together with the remaining components, are treated in the normal way. For example SP-5 or SP-6.2 may apply.

Examples:

trispiro{bis(cyclohexane)-1,4':1",6'-furo[3,4-d][1,3]oxathiole-2',14'''-[7]oxadispiro[5.1.5.2]pentadecane}
CAS index name
pentaspiro[tetracyclohexane-1,2'(5'H):1''',5':1"",4"(6"H):1""'6"-furan-3'(4'H),2"-furo[3,4-d][1,3]oxathiole]

trispiro{1-oxaspiro[2.3]hexane-2,3':4,3":5,3'''-tris(tetracyclo[3.2.0.0^2,7.0^4,6]heptane)}

Note There are only two monocyclic rings spiro-fused together.

1λ⁵,3λ⁵,5λ⁵,7λ⁵-tetraspiro{tetraspiro[2,4,6,8,9,10-hexathia-1,3,5,7-tetraphosphaadamantane-
1,2':3,2":5,2''':7,2''''-tetrakis([1,3,2]oxathiaphosphetane)]-4',7'''' ':4",7'''' '':4''',7'''' ''':4'''',7'''' ''''-tetrakis(pyrano[2,3-c]acridine)} [criterion SP-6.4 (b)]
CAS index name octaspiro[2,4,6,8,9,10-hexathia-1,3,5,7-tetraphosphatricyclo[3.3.1.1^3,7]decane-
1,2'λ⁵:3,2"λ⁵:5,2"'λ⁵:7,2''''λ⁵-tetrakis[1,3,2]oxathiaphosphetane-4',7''''':4",7'''''':4''',7''''''':4'''',7''''''''-tetrakis[7H]pyrano[2,3-c]acridine]

Note 1 The primes have a space after every four to assist recognition of the number present.

Note 2 See SP-7 for the use of the λ symbol with non-standard valency.

SP-7 Spiro systems containing atoms with non-standard valency

SP-7.1 In addition to the normal use of the lambda symbol (ref 11) there are a number of special situations with spiro systems. Non-standard valency is stated in the normal way with the appropriate locant when cited as part of the name, otherwise at the start of the name. If the spiro atom has non-standard valency the symbol is associated with the less primed locant and is placed at the front of the name except for cases described in SP-7.2. Where there is a choice the first cited component (unprimed locants in a spirobi[....] type name) is used for indicated hydrogen.

Note CAS index names differ from the above in that the lambda symbol is associated with the more primed locant at a spiro-fusion site and is separately quoted in front of a spirobi[....] type name. As noted below CAS index names do not always name the mancude system (ref 13).

Examples:

3H-2λ⁵-spiro[1,3,2-benzoxazaphosphole-2,2'-[1,3,5,2]tiazaphosphinine]
CAS index name spiro[1,3,2-benzoxazaphosphole-2(3H),2'λ⁵-[1,3,5,2]trazaphosphorine]

2,3-dihydro-1'H-2λ⁵-spiro[1,3,2-benzoxazaphosphole-2,'-[1,3,5,2]triazaphosphinine]
CAS index name spiro[1,3,2-benzoxazaphosphole-2,2'λ⁵(1'H)-[1,3,5,2]tiazaphosphorine]

1H-2λ⁵,2'-spirobi[[1,3,2]benzodiazaphosphinine]
CAS index name for the 1',2'-dihydro compound is 2λ⁵-2,2'(1H,1'H)-spirobi[1,3,2-benzodiazaphosphorine]

1,5,9,13-tetraoxa-7,14-diaza-6λ⁵,8λ⁵-diphosphadispiro[5.1.5.1]tetradecane

2λ⁵-spiro[1,3,2-benzodioxaphosphole-2,11'-[1,3,2]oxazaphospholo[3',2':2,3][1,2,4,3]triazaphospholo[4,5-a]pyridine]

1'H,4'H,8'H-2λ⁵-spiro[1,3,2-benzodioxaphosphole-2,3a²'-[3a²]phosphadibenzo[cd,mn]pyrene]
CAS index name spiro[1,3,2-benzodioxaphosphole-2,13'λ⁵-[1H,4H,8H]benzo[1,9]phosphinolizino[3,4,5,6,7-defg]acridophosphine

Note The internal number used here follows IUPAC fused ring nomenclature rule FR-5.5.2 (ref 16).

2H,2'H,6H,6'H-8λ⁶,8'-spirobi[[1,2]oxathiolo[4,3,2-hi][2,1]benzoxathiole]
CAS names this as an octahedral derivative of sulfur

3H-2λ⁵-spiro[1,4,2-oxazaphosphole-2,1'-[2,8,9]trioxa[1]phosphaadamantane] (preferred name)
Alternative name
3H-2λ⁵-spiro[1,4,2-oxazaphosphole-2,1'-[2,8,9]trioxa[1]phosphatricyclo[3.3.1.1^3,7]decane]

SP-7.2 Where the lambda symbol is required to name the component it is cited in the normal way with the component name.

Examples:

1H,3H-2λ⁵-spiro[4λ⁵,15λ⁵-azeno[1,3,2]diazaphosphinino[1,2-a][1,3,5,7,2,4,6]tetraazatriphosphacycloundecine-2,2'-[1,3,2]diazaphosphinine]

trispiro{1,2,8,9,14,15-hexaaza-5λ⁵,7λ⁵,1λ⁵-triphosphatrispiro[4.1.4⁷.1.4¹³.1⁵]octadecane-6,9':12,9":18,9'''-tris(fluorene)} (Named using SP-6.4 then SP-6.1)
CAS index name trispiro[1,2,8,9,14,15-hexaaza-5λ⁵,7λ⁵,1λ⁵-triphosphatrispiro[4.1.4.1.4.1]octadecane-6,9':12,9":18,9'''-tris[9H]fluorene]

11. IUPAC, Treatment of variable valence in organic nomenclature (Lambda convention), recommendations 1983, Pure Appl. Chem. 56, 769-778 (1984).

13. IUPAC, Glossary of class names of organic compounds and reactive intermediates based on structure, recommendations 1995, Pure Appl. Chem. 67, 1307-1375 (1995).

16. IUPAC, Nomenclature of fused and bridged fused ring systems, recommendations 1998, Pure Appl. Chem. 70, 143-216 (1998).