Ion-molecule reactions in the gas phase. Part 1. Stereospecific nucleophilic substitution of tertiary alcohols by ammonia

Abstract

A study of the chemical ionisation of two pairs of diastereoisomeric unsaturated tertiary alcohols with isobutane as the protonating gas shows that hydrogen bonding between the protonated hydroxy-group and the double bond can stabilize the quasi-molecular ion, if the geometry is correct. Therefore, it is possible to differentiate between two isomers. With ammonia, the most interesting phenomenon is an S_N2-like reaction, in which the OH₂⁺ group is replaced by NH₃⁺, with Walden inversion.