The electron impact mass spectra of twenty acetates and methylates of spirostanol and related furostanol glycosides of high molecular weight (above 650) have been investigated, and the most probable fragmentation patterns of the glycoside derivatives are presented. High resolution mass spectrometry provides useful information concerning the structures of both aglycone and sugar moieties as well as the molecular size of the oligoglycosides.

Thermal decomposition of diphenyl phosphoramidate (1)and phenyl phosphordiamidate (2) was investigated by DTA-TG, IR, 1H NMR, 31P NMR, mass spectroscopy, and TG-GC/MS. The DTA-TG/DTG curve showed that the thermal decomposition of 1 occurred in one stage. Compound 1 melted at about 150°C and decomposed to polyphosphates accompanied with a weight loss of about 60% in the temperature region of 200 to 350°C. It was confirmed from the results of IR, 1H NMR, and TG-GC/MS that this weight loss in TG of 1 is attributed to the liberation of ammonia and phenol and to the production of an insoluble polyphosphate through triphenyl phosphate or a soluble oligophosphate. The fragment ions of diphenyl ether (m⁄z 170) and aniline (m⁄z 93) were recognized in the mass spectrum of 1. This result indicates that phenyl radical and hydrogen atom in both samples transfer between three oxygen atoms and a nitrogen atom around a phosphorus atom. The activation energy of the thermal decomposition was estimated to be 151 kJ mol−1 for 1 and 220 kJ mol−1 for 2. From the DTA-TG/DTG curve of 2, the decomposition in TG showed two stages and proceeded in a similar process to 1. The cleavage of 2 by the electronic impact was also similar to that of 1.

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