Preparation of Primary and Secondary Azidosugars from Diols using the Dioxaphosphorane Methodology
作者:Dominique Lafont、Paul Boullanger
DOI:10.1080/07328309908544029
日期:1999.1
Treatment of methyl 2,3-di-O-benzyl-alpha-D-glucopyranoside (1), methyl 2,3-di-O-acetyl-alpha-D-glucopyranoside (4), 3-O-benzyl-1,2-O-(1-methylethylidene)-alpha-D-glucofuranose (6), 3-O-acetyl-1,2-O-(1-methylethylidene)-alpha-D-glucofuranose (9), 1,2-O-(1-methylethylidene)-alpha-D-xylofuranose (11) and methyl 2,3-di-O-acetyl-alpha-D-galactopyranoside (15) with diisopropylazodicarboxylate-triphenylphosphine in tetrahydrofuran led to the corresponding dioxaphosphoranes, which were opened by trimethylsilyl azide affording the silylated primary azidodeoxysugars. When the same reaction was performed on methyl 2,3-di-O-benzyl-alpha-D-galactopyranoside (20), an inversion of the regioselectivity of the dioxaphosphorane opening was observed, leading mainly to the 4-azido-4-deoxy-alpha-D-glucopyranoside derivative 27.