Synthesis of some monodeoxyfluorinated methyl and 4-nitrophenyl α-d-mannobiosides and a related 4-nitrophenyl α-d-mannotrioside
作者:Shaheer H. Khan、Rakesh K. Jain、Saeed A. Abbas、Khushi L. Matta
DOI:10.1016/0008-6215(90)84297-8
日期:1990.5
of diol 18 with 20 gave 4-nitrophenyl 4-O-acetyl-6-deoxy-6-fluoro-3-O- (21) and -2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha-D- mannopyranoside (23) in the ratio of approximately 2:1, together with a small proportion of a branched trisaccharide. 4-Nitrophenyl 4,6-di-O-acetyl-alpha-D-mannopyranoside was similarly glycosylated with bromide 19 to give 4-nitrophenyl 4,6-di-O-acetyl-3-O- and
用N,N-二乙基氨基硫磺处理甲基3,4,6-三-O-苄基-2-O-(2,3,4-三-O-乙酰基-α-D-甘露吡喃糖基)-α-D-甘露吡喃糖苷三氟化物(Et2NSF3),然后进行O-脱乙酰化和催化氢解,得到甲基2-O-(6-脱氧-6-氟-α-D-甘露吡喃糖基)-α-D-甘露吡喃糖苷(8)。甲基6-脱氧-6-氟-2-O-α-D-甘露吡喃糖基-α-D-甘露吡喃糖苷(11)类似地从甲基3-O-苄基-2-O-(2,3,4,6 -四-O-乙酰基-α-D-甘露吡喃糖基-α-D-甘露吡喃糖苷1,2,3,4-四-O-乙酰基-6-脱氧-6-氟-β-D-甘露吡喃糖(13),通过处理1,2,3,4-四-O-乙酰基-β-D-甘露吡喃糖获得用于合成8和11的4-硝基苯基类似物及其3-O-连接的异构体的化合物用Et2NSF3在氯化锡(IV)存在下用4-硝基苯酚处理13 然后依次进行O-脱乙酰基,异丙基化,乙酰化和缩醛基