AN INVESTIGATION INTO THE STEREOCHEMISTRY OF THE BORONATE DI-ESTERS OF SOME MONOSACCHARIDES USING TANDEM MASS-SPECTROMETRY

The aim of this work was to probe the stereochemistry of a series of m onosaccharides. Firstly, the underivatized sugars were investigated us ing linked-scans and tandem mass spectrometry on a 'hybrid' instrument (hybrid MS/MS) and secondly, a comparison of linked-scan and hybrid M S/MS was carried out on the butyl and phenyl boronate di-esters. In si tu derivatization of the sugar to the boronate di-ester allows a negat ive-ion fast-atom bombardment (FAB) investigation with greater sensiti vity than for the underivatized sugar. The linked-scan data allow a gr eat deal of information on the structure and chemistry of the sugars t o be obtained, but the sensitivity at lower mass is limited. The hybri d MS/MS data give similar fragmentation information, plus improved sen sitivity at lower molecular weight.