332 



INOSITOLS 



hexane^"' ^^ and upon the various hexachlorocyclohexanes.^^ If the con- 

 ceptions appHed to cyclohexane and its derivatives are extended to the 

 cyclohexitols, it will be seen that six of the substituents (hydroxyl or 

 hydrogen) surround the ring of carbon atoms in an equatorial belt; the six 

 others are perpendicular to the plane formed by the carbon ring: three 

 above (north polar), three below (south polar). Each carbon atom mil 



TABLE II 

 Spatial Configurations of Cyclohexitols" 



" Based on the chair configuration and on the numbering system of Magasanik and Chargaflf.* 



therefore carry one polar and one equatorial substituent. A twist of the six 

 carbon atoms through a single plane to the opposite chair form renders the 

 equatorial substituents polar and vice versa}^ Two geometrically tautomeric 

 forms will, consequently, exist for each inositol isomer. By analogy to the 

 methyl-substituted cyclohexaneSj^" it may, however, be assumed that the 

 tautomer possessing the smaller number of polar hydroxyls will predomi- 

 nate. 



The constellations of the hydroxyl groups in the chair forms of the iso- 



" F. D. Rossini and K. S. Pitzer, Science 105, 647 (1947). 



22 O. Bastiansen, p. Ellefsen, and O. Hassel, Research (London) 2, 248 (1949). 



