engleski

Preparative Separations of Enantiomeric Diaziridines by Liquid Chromatography on Triacetylcellulose. Racemizations Monitored by Polarimetry and by 1H NMR

Enantiomeric diaziridines have been partially separated by chromatography on triacetylcellulose. (-)-2, (+)-4 and (-)-4 were obtained almost pure, enatiomeric purities (Table 1) being measured by 1H NMR in the presence of optically active additives. The same procedure was tested for monitoring racemizations (Table 2) which were also studied, with higher accuracy, by polarimetry. The barriers to nitrogen inversion, converting the trans- diaziridines 2 and 4 in to cis-intermediates, are compared with known  G* values.

diaziridines; separation of enantiomers; barriers to nitrogen inversion

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