Components for a combinatorial library of rigid azabicyclic alpha-L-fucosemimics: First X-ray crystal structure of a stable monoalkylated triazene formed by hydrogenation of an azide

Photobromination of the rigid aza-bicyclic fucose mimic 3 gave a reactive g lycosyl type bromide 7 as a divergent intermediate for the synthesis of bot h 7-O and 7-N linked bicyclic L-fucose derivatives by direct displacement w ith alcohols or amines. Displacement of the bromide 7 with sodium azide gav e an azide 6 which on hydrogenation gave a stable monoalkyl triazene 5 the structure of which was established by X-ray crystallographic analysis. Hydr olysis of 7 allowed access to a monocyclic L-fucose mimic with a nitrogen s ubstituent at C-5. (C) 1999 Elsevier Science Ltd. All rights reserved.