Electron ionization mass spectra of acetals of beta-D-glycopyranosylnitromethanes

O-Isopropylidene and O-benzylidene acetals of common 2,6-anhydro-1-deoxy-1- nitroalditols (beta-D-glycopyranosylnitromethanes) derived from D-glucose, D-galactose and D-mannose were studied by electron ionization (EI) mass spe ctrometry, Fragment pathways of the title compounds were studied using accu rate mass measurements, collision-induced dissociation, B-2/E and B-2/E mea surements of selected ions and mass spectra of O-deuterium-labelled compoun d. The fragmentation pathways and some differences found among the mass spe ctra of stereoisomers are discussed. Noteworthy is the splitting off of the (NO2)-N-. radical and elimination of acetone from the molecular ions of 4, 6-O-benzylidene-2,3-O-isopropylidene-beta-D-galactopyranosylnitromethane. T his fragmentation route of relatively high abundance was not observed in th e case of D-gluco and D-manno analogues. The differences in the EI mass spe ctra of stereoisomers may help to provide some information serving for the estimation of the stereochemical arrangement of compounds of this type. Cop yright (C) 1999 John Wiley & Sons, Ltd.