Glycosylidene Carbenes. Part 14. Glycosidation of partially protected galactopyranose-, glucopyranose-, and mannopyranose-derived vicinal diols
作者:Pulla Reddy Muddasani、Eva Bozó、Bruno Bernet、Andrea Vasella
DOI:10.1002/hlca.19940770128
日期:1994.2.9
respectively (Scheme 1, Table 3). The disaccharides derived from 4, 5, and 7 were characterized as their acetates 18/19/22/23, 26/27/30/31, and 38/39/42/43, respectively. Glycosidation of the galacto-configurated diequatorial 2,3-diols 8 and 9 and the manno-configurated diequatorial 3,4-diol 10 by 1 (Scheme 2, Table 3) also proceeded in fair yields to give the disaccharides 44–47 (69–80%;1,2-/1,3-linked products
考察了在赤道反式-1,2和轴向赤道顺式1,2-二醇中的H键与二嗪1的糖基化的区域选择性之间的关系。根据FT-IR和1 H-NMR光谱分配H键(图1)。苷化由1所述的葡糖-构型diequatorial反式-2,3-二醇4-7,得到单-葡糖产品16/17/20/21(69-89%); 1,2- / 1,3-链接产品(37-46:63-54),24 /25/28/ 29(60-63%; 1,2- / 1,3-链接产品46-51:54 –49),32–35(69-94%; 1,2- / 1,3-链接的产品45-52:55-48)和36/37/40/41(59-63%; 1,2- / 1,3-链接的产品产品52–59:48–41)(方案1,表3)。衍生自4、5和7的二糖的特征分别是其乙酸盐18/19/22 / 23、26 / 27/30/31和38/39/42/43。所述的糖苷化半乳-构型diequatorial