Zhang M, Du Y, Kong F
Research Center for Eco-Environmental Sciences, Academia Sinica, Beijing, People's Republic of China.
Carbohydr Res. 2001 Feb 15;330(3):319-24. doi: 10.1016/s0008-6215(00)00303-7.
A practical synthesis of fully benzoylated tetrasaccharide, whose free form is indispensable to the antibiotic ristomycin A for the process of dimerization and binding to the cell wall, was achieved via sequential assembly of the building blocks, allyl 3,4-di-O-benzoyl-alpha-D-glucopyranoside, 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate, 2-O-acetyl-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate, and 2,3,5-tri-O-benzoyl-alpha-D-arabinofuranosyl trichloroacetimidate. A one-pot preparation of allyl 3,4-di-O-benzoyl-2-O-tert-butyldimethylsilyl-6-O-triphenylmethyl-alpha-D-glucopyranoside is described, and regioselective glycosylation is carried out using perbenzoylated sugar trichloroacetimidates as glycosyl donors in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf).
通过依次组装烯丙基3,4-二-O-苯甲酰基-α-D-吡喃葡萄糖苷、2,3,4-三-O-苯甲酰基-α-L-吡喃鼠李糖基三氯乙酰亚胺酯、2-O-乙酰基-3,4,6-三-O-苯甲酰基-α-D-吡喃甘露糖基三氯乙酰亚胺酯和2,3,5-三-O-苯甲酰基-α-D-阿拉伯呋喃糖基三氯乙酰亚胺酯，实现了完全苯甲酰化四糖的实用合成，其游离形式对于抗生素利托霉素A的二聚化过程以及与细胞壁的结合是必不可少的。描述了烯丙基3,4-二-O-苯甲酰基-2-O-叔丁基二甲基甲硅烷基-6-O-三苯甲基-α-D-吡喃葡萄糖苷的一锅法制备，并在催化量的三甲基甲硅烷基三氟甲磺酸酯（TMSOTf）存在下，使用全苯甲酰化糖三氯乙酰亚胺酯作为糖基供体进行区域选择性糖基化。
