Abstract Boron trifluoride-catalyzed condensation of 2,3,4,6-tetra- O -benzyl-α- d -glucopyranosyl fluoride ( 2 ) with 3,4-di- O -benzoyl-1,2- O -isopropylidene-β- d -fructopyranose ( 1 ) gave preferentially the α- d -(1→5)-linked disaccharide 8 . Similarly, glycosylation of benzyl 1,3,4-tri- O -benzoyl-β- d -fructopyranoside ( 4 ) with 2 gave preponderantly a disaccharide derivative that, after cleavage
摘要
三氟化硼催化2,3,4,6-四-O-苄基-α-d-
吡喃
葡萄糖基
氟(2)与3,4-二-O-苯甲酰基-1,2-O-异亚丙基-β的缩合反应-d-
果糖吡喃糖(1)优先给出α-d-(1→5)-连接的二糖8。类似地,将苄基1,3,4-三-O-苯甲酰基-β-d-
果糖吡喃糖苷(4)糖基化,主要得到二糖衍
生物,该二糖衍
生物在苯甲酰基和苄基均被裂解后可提供白糖(5-O -α-d-
吡喃
葡萄糖基-β-d-
果糖吡喃糖; 13)。这在正交晶空间群P 2 1 2 1 2 1中结晶,该晶群在单位位置的两个单元中以4:1的比例包含四个糖和四个
水分子。如预期的那样,
果糖吡喃糖和
吡喃
葡萄糖环均分别采用2 C 5(d)或4 C 1(d)椅子构象。