作者:Alexander Heckel、Elmar Mross、Karl-Heinz Jung、Jörg Rademann、Richard R. Schmidt
DOI:10.1055/s-1998-3127
日期:1998.2
Mercaptopropyl-functionalized controlled-pore glass (MP-CPG, 2) was employed as a solid phase material for the synthesis of α(1-2)-connected trimannoside 16. As a glycosyl donor O-(3,4,6-tri-O-benzyl-2-O-phenoxyacetyl-α-d-mannopyranosyl)trichloroacetimidate (6) was employed which was readily obtained from d-mannose. Glycosylation of 2 and of intermediates 9 and 13 was performed with excess 6 in CH2Cl2 at -40 °C in the presence of TMSOTf as the catalyst (→ 7, 11, 15). For the removal of the temporary phenoxyacetyl (PA) protective group guanidine in DMF was used (→ 9, 13). Cleavage of products 7, 9, 11, 13 and 15 from MP-CPG was carried out with N-bromosuccinimide (NBS) in THF/MeOH in the presence of 2,6-di-tert-butylpyridine (DTBP) affording 8, 10, 12, 14, and methyl trimannoside 16, respectively.
巯丙基功能化可控孔隙玻璃(MP-CPG,2)被用作合成δ(1-2)-连接三甘露糖苷 16 的固相材料。作为糖基供体,使用了 O-(3,4,6-三-O-苄基-2-O-苯氧乙酰基-δ-d-吡喃甘露糖基)三氯乙酰亚氨酸(6),它很容易从 d-甘露糖中获得。以 TMSOTf 为催化剂,在 -40 °C、CH2Cl2 溶液中加入过量 6,对 2 以及中间产物 9 和 13 进行糖基化反应(→7、11、15)。为了去除临时的苯氧乙酰(PA)保护基,使用了 DMF 中的胍(→9、13)。在 2,6-二叔丁基吡啶 (DTBP) 存在下,在 THF/MeOH 中使用 N-溴琥珀酰亚胺 (NBS) 从 MP-CPG 中裂解产物 7、9、11、13 和 15,分别得到 8、10、12、14 和甲基三annoside 16。