Reversed retention order and other stereoselective effects in the separation of amino alcohols on Chiralcel OD

Abstract

The enantioselective resolution of a series of amino alcohols on Chiralcel OD was studied with respect to the effect of temperature, alcohol additive and water content in a mobile phase of hexane with added diethylamine. The chain length between the hydroxy and the amino groups in the solutes had a considerable influence on the stereoselectivity. For one of the amino alcohols a reversal of the retention order between the antipodes was obtained by varying the above parameters. The amino alcohols are retained by at least two chiral sites, one of which is highly dependent on hydrogen bonding. This bonding ability can be directly controlled by the water content of the mobile phase.