INOSITOL 



ring, whilst the formation of the inactive monophosphoric ester 

 excluded the formula with four adjacent hydroxy 1 groups on one side 

 of the ring and the other two groups on the other side. 



Oxidation of a mixture of the mono- and di-phosphoric esters of 

 w^so-inositol yielded w^so-tartaric acid and racemic tartaric acid. 

 This result excluded the formula with alternate hydroxyl groups 

 above and below the ring, since this contains only trans-hydioxyl 

 groups and therefore cannot give rise to w^so-tartaric acid on oxidation. 

 Oxidation of w^so-inositol itself by alkaline permanganate solution 

 gave a mixture of trihydroxyglutaric acid, d- (III) and l-talomucic 

 acids and d- (IV) and /-saccharic acids. This evidence indicated that 

 meso-inositol could have either formula I or formula II. 



T. Posternak * decided between these formulae by studying the 

 oxidation product obtained by the action of Acetohacter suboxydans on 

 meso-inositol. This substance, inosose (V), gave on oxidation a 

 mixture of d- (VI) and /-?^osaccharic acid and, on reduction, regenerated 

 w^so-inositol and produced at the same time another naturally occur- 

 ring cyclitol, scyllitol (VII). w^50-Inositol must therefore have the 

 structure represented by (I). 



The structure assigned to w^so-inositol by T. Posternak was con- 

 firmed by G. Dangschat and H. O. L. Fischer.^ The tetra-acetate of 

 mesoinositol, obtained from the tetra-acetyl-monoacetone derivative 

 by removal of acetone, was oxidised with lead tetra-acetate giving a 

 dialdehyde, which on further oxidation gave a mixture of the tetra- 

 acetyl derivatives of the diethyl esters of d- (VI) and /-z^osaccharic 

 acids. 



meso-inositol has been synthesised by hydrogenation of hexa- 

 hydroxybenzene.^ With Raney nickel as catalyst, a mixture of 

 meso-inositol, scyllitol and other cyclitols was formed. Scyllitol 

 crystallised out from a 50 % aqueous methanol solution and meso- 

 inositol from a 90 % aqueous methanol solution. Several attempts 

 have been made to synthesise weso-inositol by other routes, but without 

 success."^' ® 



References to Section 3 



1. L. Maqueime, Ann. Chim., 1887, 12, 80. 



2. T. Posternak, Helv. Chim. Acta, 1935, 18, 1283. 



3. R. J. Anderson, /. Biol. Chem., 191 4, 18, 441. 



4. T. Posternak, Helv. Chim. Acta, 1942, 25, 746. 



5. G. Dangschat and H. O. L. Fischer, Naturwiss, 1942, 30, 146. 



6. H. Wieland and R. S. Wishart, Ber., 1914, 47, 2082 ; R. C. 



Anderson and E. S. Wallis, /. Amer. Chem. Soc, 1948, 70, 

 2931. 



7. F. Micheel, Annalen, 1932, 496, 77. 



8. Y. Hamamura, Proc. Imp. Acad. Tokyo, 1934, 10, 459. 



566 



