The oxidation of some aldose sugars and sugar derivatives by alkaline solutions of iodine.

An analytical method for the estimation of aldoses in solution by a quantitative oxidation to the corresponding aldonic acids, using alkaline solutions of iodine as the oxidising agent, has been described in a number of papers (1). In all cases, it seems to have been assumed that the iodine first reacts with the alkali to form hypoiodite, and that this latter is the active oxidising agent. No definite evidence, however, has been brought forward in support of this assumption. At the same time, varying degrees of alkalinity and other conditions have been recommended by the several authors for carrying out the oxidation. Accordingly, the project undertaken was an attempt to clarify the position by a study of the mechanism of aldose oxidation in alkaline solutions of iodine. In the course of the work, however, it became apparent that configurations of the sugars exercised -a considerable effect on the rate of oxidation, and this effect was also studied. These investigations have shown a need for much more work in various closely related directions Which promise to yield information of value; hence a section has been included wherein they are outlined, together with some preliminary work in these directions which the author has carried out, but which lack of time has forced temporarily to be abandoned.