The assembly of oligosaccharides from “standardized intermediates”: β-(1→3)-linked oligomers of d-galactose
作者:Manjit S. Chowdhary、Juan L. Navia、Laurens Anderson
DOI:10.1016/0008-6215(86)80014-3
日期:1986.8
Several 2-O-benzoyl-4,6-di-O-benzyl-3-O-R-alpha-D-galactopyranosyl chlorides, designed as general precursors of beta-linked, interior D-galactopyranosyl residues in oligosaccharides, were tested in a sequential synthesis of the galactotriose beta-D-Galp-(1----3)-beta-D-Galp-(1----3)-D-Gal (19). The chlorides having R = tetrahydro-2-pyranyl and tert-butyldimethylsilyl gave excellent results, whereas
依次测试了几种2-O-苯甲酰基-4,6-二-O-苄基-3-OR-α-D-吡喃半乳糖基氯,这些寡糖被设计为寡糖中β-连接的内部D-吡喃半乳糖基残基的一般前体。半乳糖三糖β-D-Galp-(1 ---- 3)-β-D-Galp-(1 ---- 3)-D-Gal的合成(19)。具有R =四氢-2-吡喃基和叔丁基二甲基甲硅烷基的氯化物给出了优异的结果,而具有R = 3-苯甲酰基丙酰基和氯乙酰基的那些氯化物不能令人满意。还制备了具有R = 2,3-二-O-苯甲酰基-4,6-二-O-苄基-β-D-吡喃半乳糖基的活化的二糖嵌段(17),并作为糖基供体进行了测试。将17与摩尔比为1.13:1的1-丙烯基2-O-苯甲酰基-4,6-二-O-苄基-α-D-吡喃半乳糖苷(14)偶联,得到64%的三糖衍生物(18 ),可以将其转换为19。