Chemical synthesis and NMR spectra of a protected branched-tetrasaccharide thioglycoside, a useful intermediate for the synthesis of branched oligosaccharides
作者:Mohammed Saddik Motawia、Carl Erik Olsen、Birger Lindberg Møller、Jan Marcussen
DOI:10.1016/0008-6215(94)90006-x
日期:1994.1
6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl- alpha-D-glucopyranosyl) -alpha,beta-D-glucopyranosyl trichloroacetimidate (9), which was effectively used as the glycosyl donor in the condensation reaction with compound 4, using trimethylsilyl triflate as catalyst, to obtain the branched tetrasaccharides phenyl O-[2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranosyl)- (1-->4)]-O-(2,3,6-tri-O-benzyl-alpha-D-glucopyranosyl)-(1-->6)-O-(2
过O-乙酰化的1,6-脱水麦芽糖(3)的酸催化硫酚反应生成苯基2,3-二-O-乙酰基-4-O-(2,3,4,6-四-O-乙酰基-α -D-吡喃葡萄糖基)-1-硫代β-D-吡喃葡萄糖苷(4)的定量产率。苯基4-O-α-D-吡喃葡糖基-1-硫代-β-D-吡喃葡糖苷(5)是通过使用三甲基甲硅烷基三氟甲磺酸酯作为催化剂,通过酸催化麦芽糖八乙酸酯(2)的硫酚基化而得到的。5的标准苄基化反应生成苯基2,3-二-O-苄基-4-O-(2,3,4,6-四-O-苄基-α-D-吡喃葡萄糖基)-1-硫代-β-D-葡萄糖苷(6),在丙酮水溶液中用N-溴琥珀酰亚胺处理后,得到2,3,6-三-O-苄基-4-O-(2,3,4,6-四-O-苄基-α- D-吡喃葡萄糖基)-D-吡喃葡萄糖(8)。在无水碳酸钾存在下,用三氯乙腈处理化合物8,得到2,3,完整的NMR解释为10。研究了支链四糖合成的替代方法。苯基硫代糖苷5的化学合