Bivalent substitution prefixes

Where the new bridge is attached to oxygen (or a replacement heteroatom, e.g. nitrogen in an amino sugar) already indicated in the name of the unbridged carbohydrate, the bivalent substituent prefix denotes substitution at two heteroatoms as outlined in 2-Carb-24.1 and 2-Carb-25 [method (b)]. Heteroatoms not directly bonded to the carbohydrate chain are regarded as part of the bridge. 

Imines. The group >C=NH is named either by the suffix -imine or by citing the name of the bivalent radical R R C< as a prefix to amine. For example, CH3CH2CH2CH=NH could be named 1-butanimine or butylideneamine. When the nitrogen is substituted, as in CH2=N—CH2CH3, the name is A-(methylidene)ethylamine. 

Bivalent Sulfur. The prefix thio, placed before an affix that denotes the oxygen-containing group or an oxygen atom, implies the replacement of that oxygen by sulfur. Thus the suffix -thiol denotes — SH, -thione denotes —(C)=S and implies the presence of an =S at a nonterminal carbon atom, -thioic acid denotes [(C)=S]OH [(C)=0]SH (that is, the O-substituted acid and the 5-substi-... 

Radicofunctional Nomenclature. The procedures of radicofunctional nomenclature are identical with those of substitutive nomenclature except that suffixes are never used. Instead, the functional class name (Table 1.9) of the compound is expressed as one word and the remainder of the molecule as another that precedes the class name. When the functional class name refers to a characteristic group that is bivalent, the two radicals attached to it are each named, and when different, they are written as separate words arranged in alphabetical order. When a compound contains more than one kind of group listed in Table 1.9, that kind is cited as the functional group or class name that occurs higher in the table, all others being expressed as prefixes. 

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