Differential gas–liquid chromatographic behaviour in diastereoisomeric systems. Part I. Symmetrically substituted dichiral hydrocarbons and ester precursors

Abstract

Dichiral molecules are defined as those with two asymmetric centres. In the present work, the differential g.l.c. behaviour of diastereomers of 2,3-dipentylbutanes and 2,4-dipentylpentanes, wherein the pentyl groups were selected from various isomeric C₅H₁₁ moieties and cyclopentyl, have been examined. Also obtained were comparable results for synthetic precursors to these compounds, the respective diethyl αα′-dipentylsuccinates and αα′-dipentylglutarates, the diacetates of 2,3-dipentylbutane-1,4-diols and 2,4-dipentylpentane-1,5-diols, and for by-product 3,4-dipentyltetrahydrofurans and 3,5-dipentyltetrahydropyrans. The experimental data provide information on configuration of the diastereomers, the effect of substituent bulk, the influence of distance between chiral centres, and the role of polar dipole–dipole interactions versus steric effects.