Structure determination by two‐dimensional NMR of α‐hydro‐ω‐butyloligostyrenes fractionated by liquid chromatography

Abstract

Abstract Two aspects of the reversed‐phase liquid chromatographic separation of α‐hydro‐ω‐butyloligostyrene stereoisomers are presented. In the first part, two‐dimensional NMR is employed to make stereochemical assignments on isolated dimer, trimer and tetramer species. This work established the elution pattern of the stereoisomers as isotactic, heterotactic and syndiotactic for tetramers. In the second part, the elution behavior of these stereoisomers in reversed‐phase chromatography is compared to that observed in size exclusion chromatography, and these comparisons suggest that differences in the effective sizes of the stereoisomers are important factors in their separation.