Isorotation Rules structure

Hudson isorotation rules. For anomeric (a and (3) sugars, Hudson s isorotation rule states that (1) the rotation of carbon 1 in many sugar derivatives is affected in only a minor degree by changes in the structure of the rest of the molecule and (2)... 

Hudson s isorotation rule was subsequently expanded by Whiffen, who suggested a set of empirical rules based on additive contributions to the molecular rotation based on contributions along each asymmetrically substituted bond. He established six structural parameters and assigned to each of these a numerical value, making possible an estimation of the molecular rotation in aqueous solution of the various pyranoses.195... 

OPTICAL SUPERPOSITION, THE ISOROTATION RULES, AND THE INFLUENCE OF STRUCTURE ON OPTICAL... 

The hypothesis of the additive nature of the rotatory contributions of the individual asymmetric centers of steroisomers in making up the total rotation of each isomer was formulated by van t Hoff and has been known as the principle of optical superposition. In its full generalization as applied to all substances, the hypothesis of optical superposition is definitely unsound and thus it is not a principle nevertheless, it has been shown by Hudson (116) that the hypothesis holds in first approximation for a large number of carbohydrates, and the approximation is sufficiently close to permit valuable inferences concerning structure and configuration to be drawn from comparisons of the rotations of carbohydrates through the application of his Isorotation Rules. 

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