Electron impact mass spectrometry of some ketosugar derivatives

The electron impact fragmentation of 1,2-O-isopropylidene-alpha-D-glycero-tetros-3-ulofuranose has been studied with the help of deuterium and 18O labelling. The effect of substituting a hydrogen atom of C-4 for a CH3 radical and that of replacing the carbonyl function with a cyanomethylenic substituent is also reported.