Nomenclature of Carbohydrates (Recommendations 1996)

2-Carb-20

Continued from 2-Carb-19

Contents

2-Carb-20. Aldonic acids

2-Carb-20.1. Naming

Aldonic acids are divided into aldotrionic acid, aldotetronic acids, aldopentonic acids, aldohexonic acids, etc., according to the number of carbon atoms in the chain. The names of individual compounds of this type are formed by replacing the ending '-ose' of the systematic or trivial name of the aldose by '-onic acid'.

Examples:


D-Gluconic acid


D-Gluconate


2-Amino-2-deoxy-D-gluconic acid

2-Carb-20.2. Derivatives

Salts are named by changing the ending '-onic acid' to '-onate', denoting the anion. If the counter ion is known, it is given before the aldonate name.

Example:

Sodium D-gluconate

Esters derived from the acid function are also named using the ending '-onate'. The name of the alkyl (aryl, etc.) group is given before the aldonate name. Alternative periphrase names like 'aldonic acid alkyl (aryl, etc.) ester' may be suitable for an index.

Amides are designated by the ending '-onamide', and nitriles by the ending '-ononitrile'.

Examples:


Methyl D-gluconate


Isopropyl 3,4-di-O-methyl-L-mannonate


N,N-Dimethyl-L-xylonamide


Methyl 3-deoxy-D-threo-pentonate


Methyl tetra-O-acetyl-L-arabinonate

Lactones are named with the ending '-onolactone'. The locants must be given (in the form '-ono-i,j-lactone): that of the carbonyl group (i) is cited first, and that of the oxygen (j) second (see examples below). Periphrase names (see alternatives in parentheses) appear widely in the literature but are not recommended. Lactams are named similarly by use of the ending '-onolactam'.

Examples:


D-Glucono-1,4-lactone
(L-Gluconic acid γ-lactone)


D-Glucono-1,5-lactone
(L-Gluconic acid δ-lactone)


3-Deoxy-D-ribo-hexono-1,5-lactone


5-Amino-5-deoxy-D-mannono-1,5-lactam

Acyl halides are named by changing the ending '-onic acid' to '-onoyl halide'.

Example:


Penta-O-acetyl-D-gluconoyl chloride

More complicated examples of general principles for naming acid derivatives can be found elsewhere [13,14].

References

13. IUPAC Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F and H, 1979 Edition, Pergamon Press, Oxford, U.K. Sections E and F are reprinted in ref. 2, pp. 1-18 and 19-26, respectively.

14. Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, Blackwell Scientific Publications, Oxford (1993).

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