Efficient Routes to Ethyl‐2‐Deoxy‐2‐phthalimido‐1‐β‐<scp>D</scp>‐thio‐galactosamine Derivatives via Epimerization of the Corresponding Glucosamine Compounds
作者:Markus Hederos、Peter Konradsson
DOI:10.1081/car-200061584
日期:2005.4.1
Short synthetic routes to protected ethyl 2‐deoxy‐2‐phthalimido‐1‐β‐D‐thio‐galactosamine derivatives via epimerization of the corresponding glucosamine compounds are described. Starting from D‐glucosamine hydrochloride, the epimerizations were performed by displacement of presynthesized triflates with nitrite anions and by an oxidation/reduction route. The latter method involved Moffatt oxidation to
描述了通过相应的葡糖胺化合物的差向异构化来生成受保护的乙基2-脱氧-2-邻苯二甲酰亚胺基-1-β-D-硫代-半乳糖胺衍生物的短合成路线。从D-氨基葡萄糖盐酸盐开始,差向异构化是通过用亚硝酸根阴离子置换预合成的三氟甲磺酸酯并通过氧化/还原途径进行的。后一种方法涉及将Moffatt氧化为相应的4-酮己糖,然后在THF中使用硼氢化钠/四丁基硼氢化铵,硼氢化锌或三仲丁基硼氢化锂还原。发现置换路线是3-O-酰基(苯甲酰基)衍生物差向异构化的首选方法。对于具有3-O-醚基(烯丙基或苄基)和6-O-苄基保护基的葡糖胺化合物,氧化/还原途径是获得相应的半乳糖胺化合物的最方便方法。产生的半乳糖胺衍生物将是合成抗冻糖蛋白物质及其类似物的有用组成部分。