Synthesis of (1 -> 3)-C and homo(1 -> 3)-C-linked iminodisaccharides starting from levoglucosenone and isolevoglucosenone
The reaction of 2,5-(benzyloxycarbonyl)imino-2,5-dideoxy-3,4-O-isopropylidene-L-ribose ((-)-15) with levoglucosenone (5) in the presence of Et2AlI gave a 3,4-dideoxy-D-glycero-hex-3-enopyranos-2-ulose derivative ((-)-16) that was converted into the (1-->3)-C-linked imino-disaccharide: methyl 3,4-dideoxy-3-[(1'S)-2',5'-dideoxy-2',5'-imino-D-ribitol-1'-C-yl)-alpha- D-lyxo-hexo-pyranoside ((+)-22). The addition of benzyl alcohol to isolevoglucosenone (3), followed by cross-aldol condensation with 3,6-[tert-butoxycarbonyl]imino-2,3,6-trideoxy-4,5-O-isopropylidene-L-ara bino-hexose ((+)-30) generated, after water elimination, a single enone ((+)-31) that was converted into a homo-(1-->3)-C-linked imino-disaccharide: 3-deoxy-3-(1',2',3',6'-tetradeoxy-3',6'-imino-L-arabino-hexitol-1'-C-yl) -beta-D-galactofuranose (44).
Keywords: Aza-c-disaccharides ; alpha ; beta-unsaturated carbonyl compound ; 1-acylethenyl anion equivalent ; immunodeficiency virus type-1 ; h-type-ii ; conformational differences ; imino disaccharides ; organic-synthesis ; n-butyldeoxynojirimycin ; preferred conformation
Univ Lausanne, BCH, Chim Sect, CH-1015 Lausanne, Switzerland. Univ Sevilla, Dept Quim Organ, E-41071 Seville, Spain.
Record created on 2005-11-09, modified on 2016-08-08