Epi-meso-Inosose

See Fletcher s review (Ref. 1, p. 62), where they are named epi-meso-inosose and scyllo-meso-inosose, respectively. 

The question of the configuration of epi-meso-inosose has recently been answered by Posternak. Examination of the formula for meso-inositol (V) will reveal that oxidation might give rise to six inososes. Attack at the equivalent positions one and three would give the enantio-morphous pair of inososes (XXXIII and XXXIV). In precisely the same manner, oxidation of carbons four and six would give the enantio-morphous pair XXXV and XXXVI. On the other hand, oxidation at either position two or five would result in the formation of the sym-... 

D,L-talomucic and D,L-glucosaccharic acids. epi-meso-Inosose is therefore the racemate represented by XXXIII and XXXIV while the reduction product epi-inositol is II, representing as it does, an inversion of... 

In 1939, Kluyver and Boezaardt observed that a particular strain of Acetobacter suboxydans (Kluyver et de Leeuw) was capable of oxidizing mcso-inositol in 90% yield to an inosose which had the same melting point as the epi-meso-inosose made chemically by Posternak in 1936. Supplied with a culture of the microorganism, Posternak confirmed this observation and showed that, while the optically inactive product of biochemical oxidation resembled very closely that obtained by nitric acid oxidation, the derivatives such as the acetate and benzoate serve to distinguish the two substances. With alkaline acylating reagents this inosose yielded tetrahydroxybenzene derivatives, as had epf-meso-inosose. 

Cautious nitric acid oxidation of meso-inositol afforded Postemak a pentahydroxycyclohexanone. Reduction of this compound or its pentaacetate gave a new inositol which Postemak named epi-inositol. Proof of the structure of the pentahydroxycyclohexanone epi-meao-inosose, see the following section) as a racemic mixture of 1-keto- and 3-keto-meso-inositol (XXXIII and XXXIV) demonstrated that ept-inositol corresponds to formula II. 

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