Abstract Water loss from frans-sobrerol upon electron impact ionization selectively involves the tertiary OH group, predominantly occurring by a stereocontrolled H-transfer from C (5) position in a rate-determining step process, as proved by 18 O 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 ...
