Ion/molecule reactions in the gas phase: Comparison of the enantioselectivity of two chiral gases

Stereochemistry study has always been a very important subject, but the determination of chirality has become potentially possible with the emergence of chemical ionization. In this study, mass spectrometry and tandem mass spectrometry (MS/MS) were used as a tool for distinguishing the isomers of (+) and (−) isopinocampheols and (+) and (−) menthols by ion/molecule reaction in the gas phase using two different chiral gases, G. The reactive plasma is made up of the ion GH+. Interactions between the plasma and the isomer M of (+) and (−) isopinocampheols and (+) and (−) menthols lead to the formation of the ions [M‐M2O+H]+, [M‐H2O+GH]+, [M+GH]+ and [2M+H]+. In mass spectrometric analysis, their relative intensities differ because of the absolute configuration of M. In MS/MS the relative intensities of the daughter ions of [M‐H2O+GH]+ ions enable a positive determination of (+) and (−) isomers. The susbtitution ion [M‐H2O+GH]+ arises via an SN2 pathway that is regioselective and sterospecific.