The catalytic oxidation of inositols and the solvolysis of their monotosyl esters

The oxidation of inositols by aeration in aqueous solution in the presence of a platinum catalyst is described in Part I of this thesis. The six isomers, eni, cis-, scyllo-, (-)-, neo-, and allo-inositols, and two methyl ethers, quebrachitol and dambonitol were oxidized and the oxidation products identified. The results are discussed with reference to the corresponding results for oxidation by Acetobacter suboxydans. It was established that only axial hydroxyl groups were dehydrogenated. This also holds for oxidation by Acetobacter suboxydans. Catalytic oxidation differs from enzymatic oxidation in two respects. Firstly, the action stops at the monoketone stage except in the case of alloinositol. Aeration of alloinositol in the presence of platinum catalyst gave a diketone and a monoketone which was not an intermediate in the formation of the diketone. Secondly, the presence of adjacent methyl groups, as in dambonitol, does not prevent oxidation. Two new monotosyl esters of inositols were prepared and the solvolysis of a number of monotosyl esters was studied. This work is described in Part II of this thesis. In all the cases studied, solvolysis occurred, and was mostly accompanied by inversion, but the stereochemical result varied considerably. Those solvolysis reactions provide new methods of synthesis for two of the rarer isomers, cis- and muco- inositols. It was found that the solvolysis was accompanied by a novel type of epimerisation reaction, and a preliminary study of this reaction was made.