Extended Applications of Di-tert-butylsilylene-Directed α-Predominant Galactosylation Compatible with C2-Participating Groups toward the Assembly of Various Glycosides
作者:Akihiro Imamura、Akiyoshi Kimura、Hiromune Ando、Hideharu Ishida、Makoto Kiso
DOI:10.1002/chem.200600832
日期:2006.11.24
alpha-predominant galactosylation have been extended to the construction of difficult glycan sequences. First, to investigate the compatibility of the alpha-predominant reaction with various glycosylation systems a variety of 4,6-O-DTBS-tethered galactosaminyl or galactosyl donors were synthesized efficiently, which have C2-participating groups with a wide variety of leaving groups such as alkylsulfenyl
二叔丁基亚甲硅烷基(DTBS)指导的α占主导地位的半乳糖基化的高通用性已扩展到困难的聚糖序列的构建。首先,为研究α-优势反应与各种糖基化系统的相容性,有效合成了各种4,6-O-DTBS系链的半乳糖胺基或半乳糖基供体,这些供体具有C2参与基团,具有多个离去基团,例如作为烷基亚磺酰基,卤化物,三氯乙酰亚胺基。使用糖基供体的糖基化反应的详细检查结果表明,由4,6-DTBS定向的α-半乳糖基化范围很广。在下一步中,通过采用DTBS定向的糖基化来检查alpha-GalN-Ser / Thr序列的立体选择性构建。因此,各种类型的丝氨酸和苏氨酸衍生物被糖基化,进行了高选择性的α-GalN-Ser/ Thr序列糖基化。此外,DTBS定向的半乳糖基化已成功地用于糖蛋白A的α-四糖基-Ser片段的合成。