2,6-二甲基-3,5-二氯-4-吡啶酚糖苷的合成

在相转移催化条件下, 使 a-D-乙酰基化溴代的葡萄糖、半乳糖、葡萄糖醛酸甲酯1a, 1b, 1c分别与2,6-二甲基-3,5-二氯-4-吡啶酚(俗称氯吡醇, 氯羟吡啶)作用, 合成了氯吡醇的糖苷: 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基-β-D-葡萄吡喃糖苷(2a), 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基β-D-半乳吡喃糖苷(2b), 1-O-(2'6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4-三-O-乙酰基-β-D-葡萄吡喃糖醛酸甲酯(2c)。2a, 2b, 2c分别在甲醇中氨解, 相应得到: 1-O-(2', 6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖苷(3a), 1-O(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-半乳吡喃糖苷(3b),1-O-(2', 6'-二甲基-3',5'-二氯-(4'-吡啶基)-β-D-葡萄吡喃糖醛酸酰胺(3c)。2c用CH~3ONa/CH~3OH处理, 得到1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖醛酸甲酯(3d)。

Synthesis of glycosides of 2,6-dimethyl-3,5-dichloro-4-pyridinol

Three acetyl glycosides 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-2,3,4,6-tetra-O-acetyl-b-D-g alactopyranoside and Me 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-2,3,4-tri-O-acetyl-b-D-glucop yranuronate (I) were synthesized from 2,6-dimethyl-3,5-dichloro-4-pyridinol and relevant glycosyl bromide in the presence of phase transfer catalyst. The glycosides were treated with ammonia in methanol to obtain the corresponding 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-b-D-glucopyranoside, 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-b-D-galactopyranoside and 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-b-D-glucopyranuronamide resp. I was treated with sodium methoxide in methanol to obtain Me 1-O-(2',6'-dimethyl-3',5'-dichloro-4'-pyridyl)-b-D-glucopyranuronate.