Thiosugars. VI—mass spectrometry of 2,3‐epithio‐ D ‐allose derivatives

The behaviour under electron impact of methyl 2,3‐dideoxy‐2,3‐epithio‐α‐ D ‐allopyranoside, methyl 2,3‐dideoxy‐2,3‐epithio‐β‐ D ‐allofuranoside, 1,6‐anhydro‐2,3‐dideoxy‐2,3‐epithio‐β‐ D ‐allopyranose, 1,6‐anhydro‐2,3‐dideoxy‐2,3‐epithio‐β‐ D ‐allofuranose and 2,3‐dideoxy‐2,3‐epithio‐β‐ D ‐allofuranose has been examined. The fragmentation pathways have been deduced by determination of the fragment ions elemental compositions, assignment of the metastable ions fröm the mass number shifts resulting from deuterium replacement, and by the comparison with an epoxide analogue.