Fragmentation processes in phthalimide- and pyridine-2,3-dicarboimidoalkyl-α-diazoketones under resonant electron capture

Resonant electron capture (REC) mass spectra of phthalimide- and pyridine-2,3-dicarboimidoalkyl-α-diazoketones have been investigated. Based on calculations using the Hartree–Fock method and density functional theory with the B3LYP functional the structure of the negative ions (NIs) [M–N₂]^? and [M–N₂–C₃H₃RO]^? as well as the reactions leading to their formation have been proposed.     

Mass spectrometry of negative ions and the stereochemistry of organic compounds. IV. Acetates of epimeric diterpene glycols

Summary 1. It has been established that the fragmentation of the molecular negative ions of the diacetates of sclareol and of 13-episclareol takes place with the splitting out of the fragments Ac, OAc, CH₂CO, AcOH, CH₃, and CH=CH₂ without skeletal rearrangements.2. The relative yields of the negative ions formed depend on the stereochemistry of the molecules of the compounds investigated.Institute of Chemistry, Bashkir Branch of the Academy of Sciences of the USSR, Ufa. Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 454–457, July–August, 1978.