Ring name index

Ring Systems File II RF 27596-RF 52845, Ring Systems File III RF 52846-RF 72861, Ring Formula Index, Ring Name Index. 

The Ring Name Index is an alphabetical list of the systematic names of all ring systems, e.g. Benzo[4,5]indeno[l,2-c]pyrrole [RF 40064]. The Ring File Number allows access to the Ring Systems File. 

Organization and use of the Ring Systems File, Ring Formula Index and Ring Name Index are, in each case, explained in detail at the beginning of the book. 

Band 4 Ring Formula Index, Ring Name Index. ... 

RAMP 160 Reboxetin 448 Ring analysis 15 Ring-chain tautomerism (tetrazole) 275 Ring formula index 16 Ring inversion see inversion Ring name index 16 Rose furan 78 Rotenone 341... 

All the systematic CA Index Names - with references to the corresponding Ring File Numbers - are listed alphabetically in the Ring Name Index (Fig. 75). In this case, as they are only the names of parent compounds, inversion of the CA Index Names is impossible. 

Fig. 75. Excerpt from the Ring Name Index to the Ring Systems Handbook...

The pyrrolopyridines contain one nitrogen heteroatom in the five-membered pyrrole ring and one nitrogen atom in the six-membered pyridine ring. A more common name is azaindoles, with 7-azaindole (l//-pyrrolo[2,3-6]pyridine (1)) being the most widely studied isomer of the series. Twelve isomers of pyrrolopyridines are listed in the Chemical Abstracts Ring Formula Index. Table 1 lists the pyrrolopyridines with their Chemical Abstracts Registry Numbers. The 1//-pyrrolopyridines (l)-(6) are the most frequently prepared, but some work has also been carried out on the isomers (7), (8), and (10). Isomers (8), (9), (11), and (12) are tautomeric structures which are considered later (see Section 7.06.4.4). 

Department of Chemistry, University of Massachusetts, Amherst, MA 01003. Cyclodiphosph(lII)azanes is commonly used nomenclature, but the more systematic ring name l,3-di>ter(-butyl-2,4-dichloro-l,3,2,4-diazadiphosphetidine is used for indexing purposes. 

The PG are named with the letters A-J depending on the type of substitution at the cyclopentane ring. The index number indicates the number of double bonds in the side chain the index number 1 characterizes derivatives of (fl//-Z)-8,l 1,14-eicosatrienoic acid, the number 2 derivatives of (a//-Z)-5,8,ll,14-eicostetraenoic acid ( arachidonic acid), and the number 3 derivatives of (a//-Z)-5,8,l 1,14,17-eicosapentaenoic acid (timno-donic acid often found in marine vertebrates). The orientation of the OH group at C-9 is designated by the index a or / . 

Many natural isocoumarins have been assigned trivial names and these are listed in the Tables and the Trivial Name Index. The numbering system of the isocoumarin ring system has led to some confusion in the past (525) the preferred system is given above and agrees with that used for the lUPAC and Chemical Abstracts preferred name H-2-benzopyran-1 -one. 

There are variations in representation of rings in different disciplines. The dye industry does not designate aromaticity or double bonds in rings. AH double bonds and aromaticity are shown in the Encyclopedia as a matter of course. For example, tetralin has an aromatic ring and a saturated ring and its stmcture appears in the Encyclopedia with its common name. Registry Number enclosed in brackets, and parenthetical CA index name, ie, tetralin [119-64-2] (1,2,3,4-tetrahydronaphthalene). With names and stmctural formulas, and especiaHy with CAS Registry Numbers, the aim is to help the reader have a concise means of substance identification. 

For single rings (i.e. mononuclear systems) up to ten atoms in size, there is no question but that Hantzsch-Widman names are overwhelmingly the most widely used, and specialists can be presumed to recognize them readily. However, when one of the trivial names of Table 1 can be used, it prevails almost exclusively. Thiophene will be immediately understood by specialists and most nonspecialists, whereas thiole will distract the reader s attention from the chemistry while he considers the writer s intention is the Hantzsch-Widman system indeed being used, or is it a typographical error Chemical Abstracts also uses these trivial names in its indexes. 

According to the systematic nomenclature these substances were first named l-f-triazolo[d] pyrimidines in compliance with the general principles of the Ring Index/ More recent papers and Chemical Abstracts indexes use the term i -triazolo[4,5-d]pyrimidine (147) in accord with the lUPAC nomenclature. The numbering of substituents when using the last-mentioned name is different from that of the 8-aza analogs. For the formulas of oxygen and sulfur derivatives names derived from the lactim or thiolactim form are almost exclusively in use (in common with the purine derivatives). These derivatives are thus described as hydroxy and mercapto derivatives, respectively. The name 1,2,3,4,6-pentaazaindene is used only rarely for this system. 

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