Syntheses of trisaccharide CDE and tetrasaccharide BCDE fragments found in orthosomycins
作者:Michel Trumtel、Paolo Tavecchia、Alain Veyrières、Pierre Sinaÿ
DOI:10.1016/0008-6215(90)84084-8
日期:1990.7
corresponds to the D-E fragment of orthosomycins. A glycosyloxyselenation-oxidation-elimination sequence was performed on 39 and either 1,5-anhydro-3,4-di-O-benzyl-2,6- dideoxy-D-arabino-hex-1-enitol (40) or 1,5-anhydro-3-O-benzyl-2,6-dideoxy-4-O-(3,4-di-O-benzyl-2,6- dideoxy-beta-D-arabino-hexopyranosyl)-D-arabino-hex-1-enitol (17) to give the C-D-E tri-and B-C-D-E tetrasaccharide fragments, respectively.
1,5-脱水-3-O-苄基-2,6-二脱氧-4-O-(3,4-二-O-苄基-2,6-二脱氧β-D-阿拉伯-己基吡喃糖基)-D-由苯基2,3-二-O-苄基-6-脱氧-4-O-(3,4-二-通过还原锂化来形成O-苄基-2,6-二脱氧-β-D-阿拉伯糖基己吡喃糖基)-1-硫代β-D-吡喃葡萄糖苷(16)。16的合成涉及苯基2,3-二-O-苄基-6-脱氧-1-硫代β-D-吡喃葡萄糖苷(9)和1,2-二-O-乙酰基-3,4的立体选择性偶联-二-O-苄基-6-脱氧-β-D-吡喃葡萄糖(14),然后在C-2'处脱氧。甲基2-O-苄基-6-脱氧-4-O-甲基-β-D-吡喃半乳糖苷(25)与3,4,6-三-O-乙酰基-2-脱氧-2-邻苯二甲酰亚胺-β-的糖基化D-吡喃葡萄糖基三氯乙酰亚胺酸酯,然后在C-2'处脱氨基,立体定向地导致甲基2-O-苄基-6-脱氧-4-O-甲基-3-O-(3,4,6-三-O-乙酰基-2-脱氧-β-D-阿拉伯双吡喃糖基)