324 INOSITOLS 



The systematic naming of derivatives of the inositols is comphcated 

 by the fact that optically inactive parent inositols can yield optically 

 active derivatives by asymmetric substitution. Furthermore, monoketo- 

 inositols may be related to two different parent inositols. It can be readily 

 appreciated how this situation gave rise to inconsistencies of nomenclature 

 as more derivatives of known types were prepared and as new types of 

 derivatives were discovered. 



TABLE I 



The Numbering of the Nine Stereoisomeric Inositols 



I II III 



Unknown cpi'-Inositol a//o-Inositol 



IV V VI 



neo-Inositol wzyo-Inositol wiHco-Inositol 



To eliminate the confusion, a systematic nomenclature for this im- 

 portant class of compounds and its derivatives was developed.- The system 

 is based on the numbering sequence sho^vn in Table I and on three rules. 



The numbering sequence provides identical numbers for stereochemically 

 equivalent carbon atoms. For d- or L-inositols the numbering begins with 

 the carbon atom marked 1 and must proceed in the designated direction. 

 Isomer IV and e'pi-, alio-, myo-, and mifco-inositols may be numbered 

 either clockwise or counterclockwise, depending on which results in the 

 lower numbers of substituents. In isomer I (all cis) and in scyllitol (all 

 trans) all carbon atoms are equivalent, and derivatives of these isomers 



^^ Since this was written, an inositol corresponding to IV has been sj'nthesized by 

 S. J. Angyal and N. K. Matheson {Abstr. 123rd Meeting, Am. Chem. Soc, p. 120, 1953) 

 and named neo-inositol. 



