SYNTHESIS OF [6''-H-3]-MALTOTRIOSE, (6''-H-2)-MALTOTRIOSE AND (2-H-2)-MALTOTRIOSE

To prepare labeled precursors for biosynthetic studies, methods for th e specific introduction of tritium and deuterium into the reducing and the terminal glucose unit of maltotriose were developed. Thus [6 ''-H -3]- and (6 ''-H-2)-maltotriose (17) and (18) were prepared via select ive methoxytritylation, deprotection and subsequent modified Pfitzner- Moffatt oxidation, followed by reduction with sodium borotritiide or s odium borodeuteride, respectively. A simple two step procedure utilizi ng the Lobry de Bruyn/van Ekenstein transformation gave (2-H-2)maltotr iose (20).