Cyclic derivatives nomenclature

The modified element name sila indicates replacement in the carbon skeleton, and similar treatment can be applied to other element names. The parent hydride names of Table 5.2 may all be adapted in this way and used in the same fashion as in the oxa-aza nomenclature of organic chemistry. In inorganic chemistry, a major use is in names of cyclic derivatives that have heteroelement atoms replacing carbon atoms in structures. It may be possible to name such species by Hantzsch-Widman procedures (see p. 77), and these should always be used when applicable. 

Organic ring systems are named by replacement nomenclature. Three- to ten-membered mono-cyclic ring systems containing uncharged boron atoms may be named by the specialist nomenclature for heterocyclic systems. Organic derivatives are named as outlined for substitutive nomenclature. The complexity of boron nomenclature precludes additional details the text by Rigaudy and Klesney should be consulted. 

Anions derived from cyclic imides may, of course, be named by the foregoing principles, but it is often desirable to name them so as to emphasize their functional character. To do so, the -imide name is changed to -imidide . Such anions are obviously mesomeric, but for nomenclature purposes they are considered to be derived from the more stable tautomer, the imide form, as shown in (201). 

The present Recommendations deal with the acyclic and cyclic forms of monosaccharides and their simple derivatives, as well as with the nomenclature of oligosaccharides and polysaccharides. They are additional to the Definitive Rules for the Nomenclature of Organic Chemistry [13,14] and are intended to govern those aspects of the nomenclature of carbohydrates not covered by those rules. 

Cyclic acetals formed by the reaction of saccharides or saccharide derivatives with aldehydes or ketones are named in accordance with 2-Carb-24.1, bivalent substituent names (formed by general organic nomenclature principles) being used as prefixes. In indicating more than one cyclic acetal grouping of the same kind, the appropriate pairs of locants are separated typographically when the exact placement of the acetal groups is known. 

Because of space limitations, only meso- and macrocycles possessing heteroatoms and/or subheterocyclic rings are reviewed in general, lactones, lactams, and cyclic imides have been excluded. In view of the delayed availability of some articles appearing in previous years, several have been incorporated. The introduction of a systematic nomenclature of catenanes, rotaxanes, and derived assemblies has recently appeared <00JPC437> this should have appeared two decades ago, but is still timely in futuristic point of view. 

Various degrees and kinds of unsaturation are possible. Unsaturation may be cumulative (which means that there are at least three contiguous carbon atoms joined by double bonds, C=C=C) or non-cumulative (which is another arrangement of two or more double bonds, as in -C=C-C=C-). In nomenclature, unsaturated cyclic parent hydrides have, by convention, the maximum number of non-cumulative double bonds. They are generically referred to as mancudes — derived from the acronym MANCUD, the MAximum Number of non-CUmulative Double bonds. Four classes of cyclic parent hydride are therefore recognised ... 

The general formula for boric acid esters is B(OR)3. The lower molecular weight esters such as methyl, ethyl, and phenyl are most commonly referred to as methyl borate [121 -43-7], ethyl borate [150-46-9], and phenyl borate [1095-03-0], respectively. Some of the most common boric acid esters used in industrial applications are Us ted in Table 1. The nomenclature in the boric acid ester series can be confusing. The IUPAC committee on boron chemistry has suggested using thalkoxy- and triaryloxyboranes (5) for compounds usually referred to as boric acid esters, trialkyl (or aryl) borates, trialkyl (or aryl) orthoborates, alkyl (or aryl) borates, alkyl (or aryl) orthoborates, and in the older literature as boron alkoxides and aryloxides. Cyclic boric acid esters, which are trimeric derivatives of metaboric acid (HB02), are known as boroxines (1). 

A special nomenclature exists for assemblies of identical cyclic units linked by single or double bonds in such a way that no new rings are created. Names are derived by combining the appropriate multiplying prefix (bi-, ter-, quater-, etc.) and either (a) the name of the cyclic unit or (b) that of the derived radical, with locants, primed where necessary, before the name indicating the positions of linkages, e.g., 53 and 54. 

Ketones. Acyclic ketones are named (1) by adding the suffix -one to the name of the hydrocarbon forming the principal chain or (2) by citing the names of the radicals R1 and R2 followed by the word ketone. In addition to the preceding nomenclature, acyclic monoacyl derivatives of cyclic compounds may be named (3) by prefixing the name of the acyl group to the name of the cyclic compound. For example,... 

The term calix[n]arenes indicates a class of phenolic metacyclophanes derived from the condensation of phenols and aldehydes. The name was coined by Gutsche and derives from the Latin calix because of the vase-like structure that these macrocycles assume when all the aromatic rings are oriented in the same direction.1 The bracketed number indicates the number of aromatic rings and hence defines the size of the macrocycle. To identify the phenol from which the calixarene is derived, the para substituent is designated by name. Thus the cyclic tetramer derived from p-f-butylphenol and formaldehyde is named p-f-butylcalix[4]arene, or with a more systematic but still simplified nomenclature proposed by Gutsche and used in this chapter 5,11,17,23-Te trakis( 1,1 -dimethylethyl)-25,26,27,28-tetrahydroxy calix [4] arene, 1 (Scheme 7.1). The systematic name reported by Chemical Abstracts is pentacyclo[19.3.1.13,7.19 13.115 19]octacosa-l (25),3,5,7(28),9,11,13(27),15,17, 19(26), 21,23-dodecaene-25,26,27,28-tetrol-5,l l,17,23-tetrakis(l, 1 -dimethylethyl). 

Ebelman and Bouquet prepared the first examples of boric acid esters in 1846 from boron trichloride and alcohols. Literature reviews of this subject are available. B The general class of boric acid esters includes the more common orthoboric acid based trialkoxy- and triaryloxyboranes, B(0R)3 (1), and also the cyclic boroxins, (ROBO)3, which are based on metaboric acid (2). The boranes can be simple trialkoxyboranes, cyclic diol derivatives, or more complex trigonal and tetrahedral derivatives of polyhydric alcohols. Nomenclature is confusing in boric acid ester chemistry. Many trialkoxy- and triaryloxyboranes such as methyl, ethyl, and phenyl are commonly referred to simply as methyl, ethyl, and phenyl borates. The lUPAC boron nomenclature committee has recommended the use of trialkoxy- and triaryloxyboranes for these compounds, but they are referred to in the literature as boric acid esters, trialkoxy and triaryloxy borates, trialkyl and triaryl borates or orthoborates, and boron alkoxides and aryloxides. The lUPAC nomenclature will be used in this review except for relatively common compounds such as methyl borate. Boroxins are also referred to as metaborates and more commonly as boroxines. Boroxin is preferred by the lUPAC nomenclature committee and will be used in this review. 

CDs are cyclic oligosaccharides containing 6, 7, or 8 glucopyranose units, referred to as a-, (3-, or y-CD, respectively. Each glucose unit contains two secondary alcohols at C-2 and C-3 and a primary alcohol at the C-6 position, providing 18-24 sites for chemical modification and derivatization (Fig. 2). Numerous derivatives have been prepared and described in the literature, but because of all the possible derivatives and positional and regioisomers, appropriate nomenclature must be used. The nomenclature should include at a minimum, the parent CD (a, (3, or y-CD) and the type and number of substituents. The substituents are usually noted by an abbreviation placed before the parent CD. Further description of the substituent group can be included with... 

The oxidation products and their derivatives, which generally exist in cyclic forms, cannot be named by the usual rules of carbohydrate nomenclature. For example, the cyclic form of the oxidation product (1) from... 

The cyclic acetals are written by extending the rules applicable to alcohol derivatives with, as a prefix, the name of the divalent radical as from general nomenclature. Two such examples are methyl 4,6-0-benzylidene-a-D-glucopyranoside 4.31 and 1,2 5,6-di-O-isopropylidene-a-D-glucofuranoside 4.32. 

The lUPAC name for the six-membered, cyclic conjugated, Hiickel-aromatic arsabenzene (3) was for some time arsenin . Since 1983 the lUPAC nomenclature has been arsinin <83PAC409). If one wants to point out that the arsenic atom is tervalent, coordination number 2, it is written as a -arsinin. Derivatives of (3) with pentavalent arsenic, coordination number 4 (7) are defined as A -aTsinines Chemical Abstracts 1,1-dihydroarsenins). 

Rigorous application of nomenclature to the hnal example, 7-6, would treat the cyclic acetal as a fused dioxole. The alternative that names the compound as a derivative of the 16,17-diol is more common. The name thus becomes 21-chloro-9a-fluoro-l l)8,16a,17a-trihydroxypregn-l,4-dien-3,20-dione 16,17-acetonide. 

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