STRUCTURE ACID SUBSTITUENT EFFECT ON CHIRAL SEPARATION OF SOME 4A-METHYL-2,3,4,4A-TETRAHYDRO-1H-FLUORENE DERIVATIVES AND 4A-METHYL-1,2,3,4,4A,9A-HEXAHYDRO-FLUOREN-9-ONE DERIVATIVES ON CTA-I AND CHIRALCEL OJ CHIRAL STATIONARY PHASES

The chromatographic parameters for 12 structurally related compounds i n the 4a-methyl-2,3,4,4a-tetrahydro-1H-fluorene and 4a-methyl-1,2,3,4, 4a,9a-hexahydro-fluoren-9-one series are reported on CTA-I and Chiralc el OJ chiral stationary phases. Arrangement of the k' values according to configurationally related enantiomer series (Class I and Class II) and not according to the actual order of elution, allows the treatmen t of the data by linear correlation with structure and substituent eff ect. A detailed analysis of the capacity factor variation with respect to the structural changes shows clearly that the framework and substi tution effects do not result in the same response on the two cellulose ester chiral stationary phases. More interestingly, it emerges that c hiral discimination may be attributed to certain areas of the molecule , these areas being different in the interaction within CTA-I and Chir alcel OJ. Furthermore, our analysis points out the relevance of attemp ting to develop quantitative relationships for configurationally relat ed series of enantiomers tin our case Class I and Class II), the main effort being devoted to the understanding of the capacity factor varia tion in each class rather than of the alpha values, which are derived entities. Chirality 10:522-527, 1998, (C) 1998 Wiley-Liss, Inc.