Synthesis of a cyanoethylidene derivative of 3,6-anhydro-d-galactose and its application as glycosyl donor
作者:Christian Vogel、Galina Morales Torres、Helmut Reinke、Dirk Michalik、Alice Voss
DOI:10.1016/j.carres.2006.09.015
日期:2007.2
corresponding bromide and both cyanoethylidene derivatives were used as donors in glycosylation reactions. The coupling with benzyl 2,4,6-tri-O-acetyl-3-O-trityl-beta-d-galactopyranoside provided exclusively the beta-linked disaccharides in approximately 30% yield. The more reactive methyl 2,3-O-isopropylidene-4-O-trityl-alpha-l-rhamnopyranoside gave with donors 3 and 7 the corresponding disaccharides in
从1,2,4-三-O-乙酰基-3,6-脱水-α-d-吡喃半乳糖开始,4-O-乙酰基-3,6-脱水-1,2-O-(1-氰基亚乙基)-通过用氰基三甲基硅烷处理合成了α-d-吡喃半乳糖(7)。另外,由相应的溴化物制备了3,4-二-O-乙酰基-1,2-O-(1-氰基亚乙基)-6-O-甲苯磺酰基-α-d-吡喃半乳糖,并且将两种氰基亚乙基衍生物用作供体。糖基化反应。与苄基2,4,6-三-O-乙酰基-3-O-三苯甲基-β-d-吡喃半乳糖苷的偶联仅以约30%的收率提供了β-连接的二糖。反应性更高的甲基2,3-O-异亚丙基-4-O-三苯甲基-α-1-鼠李糖吡喃糖苷与供体3和7一起以接近60%的收率得到相应的二糖。此外,合成了3,6-脱水-4-O-三苯甲基-1,2-O- [1-(氰基氰基)亚乙基]-α-d-吡喃半乳糖,