Nomenclature of Carbohydrates (Recommendations 1996)

2-Carb-32

Continued from 2-Carb-31

Contents

2-Carb-32. Radicals, cations and anions

Naming procedures described in this section follow the recommendations given in [25].

2-Carb-32.1. Radicals

Names for radicals are formed in the same way as those for the corresponding substituent groups (see 2-Carb-31.2).

Examples:


1,3,5,6-Tetra-O-methyl-D-fructos-4-O-yl


Tetra-O-benzyl-D-glucopyranosyl


2,3,4,6-Tetra-O-benzyl-1-methoxy-D-glucopyranosyl

Carbenes are named analogously by use of the suffix '-ylidene'.

Example:


Methyl 2-deoxy-β-D-erythro-pentopyranosid-2-ylidene

2-Carb-32.2. Cations

Cations produced by formal loss of H- from a carbon atom are denoted by replacing terminal 'e' with the suffix '-ylium', in conjunction with appropriate locants and a 'deoxy-' prefix if necessary (cf. 2-Carb-31.2).

Examples:


D-arabino-Hexos-2-C-ylium


2-Deoxy-D-arabino-hexos-2-ylium


D-Glucopyranosylium


3,4,6-Tri-O-acetyl-1,2-O-ethyliumdiyl-α-D-allopyranose

Cations formed by hydronation of an OH group or at the hemiacetal ring oxygen are denoted by the suffix '-O-ium', with numerical locant.

Examples:


Methyl 3,4-di-O-methyl-β-D-ribopyranosid-2-O-ium


Methyl 2,3,4-tri-O-methyl-β-D-ribopyranosid-5-O-ium

2-Carb-32.3. Anions

Anions produced by formal loss of H+ from an OH group are denoted by the suffix '-O-ate', with numerical locant.

Example:


Methyl 3,4-di-O-methyl-β-D-ribopyranosid-2-O-ate

Anions produced by formal loss of H+ from a carbon atom are denoted by the suffix '-ide', with appropriate locants and a 'deoxy-' prefix if necessary (cf. 2-Carb-31.2).

Examples:


D-arabino-Hexos-2-C-ide


2-Deoxy-D-arabino-hexos-2-ide


1,5-Anhydro-2,3,4,6-tetra-O-methyl-D-glucitol-1-ide

2-Carb-32.4. Radical ions

Radical ions can be named by adding the suffix 'yl' to ion names. Alternatively, the words 'radical cation' or 'radical anion' may be added after the name of the parent with the same molecular formula, especially when the location of the radical ion centre is not to be specified.

Examples:


D-Glucopyranosiumyl, or D-glucopyranose radical cation


2-Deoxy-D-arabino-hexos-2-id-2-yl
or 2-deoxy-D-arabino-hexopyranos-2-ylidene radical anion

Reference

25. IUPAC Commission on Nomenclature of Organic Chemistry, Revised nomenclature for radicals, ions, radical ions and related species (Recommendations 1993), Pure Appl. Chem., 65, 1357-1455 (1993).

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