Development of a novel sugar linkage and its application to the synthesis of bloactive compounds.

1997年，从墨西哥石竹根中分离到Coyolosa。值得注意的是，土豆是一种以乙醚为键连接的新型碳水化合物，具有显著的降血糖作用。到目前为止，还没有关于醚键连接糖链的研究报道。因此，我们研究了一种新的乙醚连接的吡喃糖的合成方法。我们采用了缩醛还原的方法，这是一种在非碱性条件下制备醚的简便方法。由于两步反应不方便，本论文还对一锅还原醚化反应进行了研究。利用上述方法，合成了各种乙醚连接的吡喃类化合物。他们的合成孔径雷达研究表明，甘露糖连接的吡喃糖具有与Coyolosa相同的降血糖活性，这表明Coyolosa的正确结构应该是甘露糖连接的吡喃糖，而不是所提出的同素连接的结构。接下来，我们研究了一种利用环氧乙烷的区域选择性开环来合成以醚键连接的稀有糖的新方法。我们还开发了一种通过1C-甲基糖的糖苷化来合成海藻糖类似物的新方法。

In 1997, coyolosa was isolated from the Acrocomia mexicana root. It is worth noting that coyolosa, which is a new carbohydrate connected by a ether-linkage, shows a significant effect on the decreasing blood glucose level. So far, no studies on the sugar linkage by ether-bonding have ever been reported. Thus, we examined a novel synthesis of ether-connected pyranoses. We adopted an acetalization-reduction procedure, which is a convenient method for the preparation of ethers under non-basic conditions. Since a two-step procedure is inconvenient, the one-pot reductive etherification was also investigated. Utilizing the method mentioned above, various ether-connected pyranoses were synthesized. Their SAR studies showed that the mannose-connected pyranose has the hypoglycemic activity as potent as coyolosa, suggesting that the correct structure of coyolosa would be the mannose-connected pyranose rather than the proposed allose-connected one. We next examined a new approach utilizing regioselective ring opening of oxirane to give the rare sugars connected by ether linkage.A novel synthesis of trehalose analogues by the glycosidation of 1C-methyl sugars is also developed.