Prefixes derivatives

Modified Forms in Common Use. There are numerous situations in which the foregoing system does not meet all requirements. In the formation uf binary compounds, several elements exhibit more Ilian two states of oxidation. One method, recommended by the IUPAC, of handling these situations is the use of prefixes derived from Greek to indicate stoichiometric composition, e.g., titanium dichloride, TiCL and dinitrogen oxide (nitrous oxide) N 0. Other accepted methods ofindicating proportions of constituents are the Stock system (oxidation number) and the Ewens-Bassett (charge number) system. 

Abbreviation for normal (unbranched), as in n-butane. naphtho The ring fusion prefix derived from naphthalene. 

By now you have noticed that names of alkanes end in -ane. Also, alkanes with five or more carbons in a chain have names that use a prefix derived from the Greek or Latin word for the number of carbons in each chain. For example, pentane, has five carbons just as a pentagon has five sides, and octane has eight carbons just as an octopus has eight tentacles. Because methane, ethane, propane, and butane were named before alkane structures were known, their names do not have numerical prefixes. Table 22-1 shows the names and structures of the first ten alkanes. Notice the underlined prefix representing the number of carbon atoms in the molecule. 

The trivial names of the common sugars, including aldoses with up to six carbon atoms and ketohexoses, are still used (Fig. 15.1). These include the d- and L-forms of glycer-aldehyde, erythrose, threose, ribose, arabinose, xylose, lyx-ose, allose, altrose, glucose, mannose, gulose, idose, galactose, and talose (El Khadem, 1988). The prefixes derived... 

Aromatic acids are named by attaching the suffix -ok acid or -ic acid to an appropriate prefix derived from the aromatic hydrocarbon. 

You add a prefix, derived from the Greek, to each element name to denote the subscript of the element in the formula. (The Greek prefixes are listed in Table 2.7.) Generally, the prefix mono- is not used, unless it is needed to distinguish two compounds of the same two elements. 

For the simplified presentation of structures, abbreviations are used which usually consist of the first letters of the name of the monosaccharide. Figure 4.1 gives the configuration prefix derived from the trivial names, representing a specified configuration applied in monosaccharide classification. Thus, systematic names for D-glucose and D-fructose are D-gluco-hexose... 

Certain diastereomeric relationships are designated by prefixes derived from two carbohydrates. o-Threose (3.2) and D-erythrose (3.3) have two stereogenic atoms and both bear an -H and an -OH group. Other molecules that differ in the analogous fashion are prefixed threo- and erythro-, as generally represented in Figure 3.5. 

In naming alkanes, the prefix derives from the longest chain of carbon atoms the suffix is "-ane." The chain is numbered so that substituents are on the lowest-numbered carbon atom. Substituents are named with the suffix "-yl" for carbon substituents and as halo e.g., in chloromethane) for haiogens. 

In principle, all radicals and ions can nowadays be named in a uniform and totally systematic manner on the basis of the operational suffixes (and prefixes derived therefrom) compiled in Table 11. Obviously, standardization of the nomenclature for such derived species can be fully congruous only if the names of the underlying parent structures themselves are generated in a thoroughly systematic way, e.g. oxidane, dioxidane, azane, diazane, etc. Hence, in the subsequent sections fully systematic names are always given as well as the conventional trivial/traditional designations. 

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