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Chiral chromatography separates enantiomers using a chiral environment, usually a chiral stationary phase. The two enantiomers form transient diastereomeric interactions with that environment and can therefore have different retention.

An ordinary achiral separation often cannot distinguish enantiomers because their bulk properties are identical in an achiral environment. A successful chiral chromatogram can measure an enantiomer ratio, provided the peaks are resolved and detector responses are interpreted correctly. Peak order alone does not establish absolute configuration without an external assignment.

Only the low-coupling pair remains, so the detected product is the trans diastereomer, with approximate coupling 4 Hz. The reaction is highly diastereoselective within the spectrum's detection limit. Its possible absolute configurations are $(2R,3R)$ and $(2S,3S)$.

A conventional proton NMR spectrum in an achiral environment cannot distinguish those enantiomers: they have the same shifts and couplings. Thus a chiral catalyst plus one set of resonances does not establish an enantiomeric excess or an absolute configuration. Chiral chromatography, an appropriate chiral NMR method, or a calibrated stereochemical comparison would be needed.