Stereocontrolled Regiospecificity of the Water Loss from trans-Sobrerol Radical Cation upon Electron Ionization

Article abstract of DOI:10.1002/oms.1210220809

Water loss from trans-sobrerol upon electron impact ionization selectively involves the tertiary OH group, predominantly occuring by a stereocontrolled H-transfer from C(5) position in a rate-determining step process, as proved by 18O and deuterium labelling.Monomethyl ethers behave accordingly.Ionic structures of the water-loss product or products are investigated by metastable ion and collision activation mass-analysed ion kinetic energy spectroscopy, using model ions generated from some substrates, which are chemically related to trans-sobrerol in condensed phase, i.e. α-pinane epoxide, cis-sobrerol and pinol.A substantial conversion of cis-sobrerol molecular ions to ionized pinol by loss of water has been demonstrated.