Separation of the enantiomers of substituted putrescine and cadaverine analogues by gas chromatography on chiral and achiral stationary phases.

Capillary gas chromatography (GC) on chiral stationary phases, i.e., Chirasil-Val [L-valine-tert.-(R)-alpha-butylamide] and XE-60-S-valine-(R)-alpha-phenylethylamide, has been applied to the resolution of various substituted analogues of putrescine as their N,N'-perfluoroacyl derivatives. The influence of the nature of the substituent on the retention behaviour and on the resolution of the enantiomers was studied. The results are discussed in terms of volatility and interaction with the chiral stationary phase. The 1,4-disubstituted putrescine analogues with two chiral centres were also clearly resolved into their corresponding stereoisomers. When the chain length between the two amino groups was increased, no clear resolution was obtained of the monosubstituted cadaverine analogues as their N,N'-perfluoroacyl derivatives. However, resolution was obtained after derivatization of the cadaverine analogues with (-)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride, followed by GC analysis on an achiral phase.