Lipid A, the hydrophobic domain of lipopolysaccharide (LPS), is a strong immunostimulator and therefore a valuable target for the development of novel immunomodulators. Various lipid A derivatives have been chemically synthesized in order to reduce toxicity while retaining the immunostimulatory activity. In this work, we describe a novel approach to the frequently problematic synthesis of monophosphorylated mono- and disaccharide lipid X using a combination of established chemistry and a novel 2-naphthylmethyl ether (Nap) protecting group for “permanent” protection of hydroxy groups. Of particular note is the fact that the key Nap protecting group is able to remain in the molecule until the final global deprotection step. Our synthetic strategy is not only efficient in regards to the yield of the various chemical transformations, but also robust in regards to the potential application of this route to the production of other lipid A analogs.

中文翻译：

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使用2-萘甲醚作为保护基团合成单磷酸化的脂质A前体。

脂质A，脂多糖（LPS）的疏水域，是一种强大的免疫刺激剂，因此是开发新型免疫调节剂的重要靶标。为了降低毒性，同时保持免疫刺激活性，已经化学合成了各种脂质A衍生物。在这项工作中，我们描述了一种新颖的方法，该方法使用已建立的化学方法和新颖的2-萘甲基甲醚（Nap）保护基团的组合来对单磷酸化的单糖和二糖脂质X进行经常有问题的合成，以“永久”保护羟基。特别值得注意的是，关键的Nap保护基团能够保留在分子中，直到最终的整体脱保护步骤为止。我们的合成策略不仅有效地提高了各种化学转化的产率，