Effect of β-cyclodextrin on the extraction of isoxazolines from aqueous ethanol into chloroform

Abstract

Regioisomeric pairs of isoxazolines were prepared through reaction of nitrile oxides with ethyl trans-cinnamate. The effect of β -cyclodextrin on the solubility of these compounds in aqueous ethanol and their extraction into chloroform has been examined. Somewhat anomalously, the compound which is least soluble in the aqueous ethanol is least efficiently extracted into the chloroform, presumably because it is most extensively complexed by the cyclodextrin. In one case, extraction of a 1:1 mixture of a regioisomeric pair of isoxazolines resulted in the separation of ca. 50% of each of the compounds in ca. 90% purity, from a single partitioning.