Ion trap MSn genealogical mapping—approaches for structure elucidation of novel products of consecutive fragmentations of morphinans

The analysis of data within multi-generational, genealogical, electrospray ionization/MSn fragmentation maps is discussed in reference to the structure elucidation of morphinans, an important class of pharmacological compounds. Various general approaches to separate and understand observed processes are discussed. These include: (1) Simple synthetic schemes incorporating deuterium and 13C into morphinans to study later-generation, O-methyl group migration; (2) labeling to understand ‘intense’ signals for even-electron to odd-electron ion ‘switching’ events; (3) gas phase ‘synthesis’ of proposed MS3 ions via an independent route, using chemical ionization (CI) MS/MS of naphthalenes and analysis via a bench-top El/Cl ion trap; (4) a useful synthetic paradigm for generating proposed carbonium ion structures at MS4 via electrospray ionization (ESI) of easily synthesized amines; (5) the analysis of an oxidation product and correlation of MSn data of a switched, odd-electron species with electron ionization and low-pressure, low-energy charge exchange data; and (6) a new way of summarizing MSn data. Copyright ­© 2000 John Wiley & Sons, Ltd.