II. CHEMISTRY 



333 



meric cyclohexitols are listed in Table II, with the use of the designations 

 and the numbering system proposed by Magasanik and Chargaff.^ The 

 scheme of Fletcher et al.^ cannot be followed for this purpose, since, as 

 may be seen in Table I, it employs two alternative routes of numbering for 

 five of the nine cyclohexitols. A system for the graphic presentation of the 

 constellations of the cyclitols has been proposed recently by Magasanik 

 et alP In this notation, which is employed for the depiction of the inositol 

 constellations in Table III, north polar hydroxyls are indicated by full 



TABLE III 

 Constellations of Cyclohexitols" 



V 



Unknown 



II 



cpi-Inositol 



III 



ai/o-Inositol 



IV 



Unknown 



V 



wjeso- Inositol 



VI 



??mco- Inositol 



VII VIII IX 



Scyllitol d-Inositol Unositol 



Based on the chair configuration. Graphic notation^': north polar hydroxyls, full circles; south 

 polar hydroxyls, open circles; equatorial hydroxyls, lines. 



circles, south polar hydroxyls by open circles, equatorial hydroxyls by 

 radial lines; the hydrogen atoms are not shown. 



The biological significance of the spatial configurations of the cyclo- 

 hexitols has been demonstrated by the selectivity, dependent upon the 

 stereochemistry of the different substrates, with which specific hydroxy! 

 groups are oxidized by Acetohacter siiboxydans to mono- or dicarbonyl 

 derivatives. These studies have led to the following rules defining the steric 

 requirements for oxidation :"* • ^^' "'^^ (1) Only polar hydroxyl groups are 

 oxidized. (2) The carbon in meta position to the one carrying the polar 

 hydroxyl group (in counterclockwise direction, if north polar; clockwise, 

 if south polar) must carry an equatorial hydroxyl group. 



B. Magasanik, R. E. Franzl, and E. Chargaff, /. Am. Chem. Soc. 74, 2618 (1952). 



