Sugar-modified nucleosides have gained considerable attention in the scientific community, either for use as molecular probes or as therapeutic agents. When the methylene group of the ribose ring is replaced with a sulfur atom at the 3’-position, these compounds have proved to be structurally potent nucleoside analogues, and the best example is BCH-189. The majority of methods traditionally involves the chemical modification of nucleoside structures. It requires the creation of artificial sugars, which is accompanied by coupling nucleobases via N-glycosylation. However, over the last three decades, efforts were made for the synthesis of 1,3-oxathiolane nucleosides by selective N-glycosylation of carbohydrate precursors at C-1, and this approach has emerged as a strong alternative that allows simple modification. This review aims to provide a comprehensive overview on the reported methods in the literature to access 1,3-oxathiolane nucleosides. The first focus of this review is the construction of the 1,3-oxathiolane ring from different starting materials. The second focus involves the coupling of the 1,3-oxathiolane ring with different nucleobases in a way that only one isomer is produced in a stereoselective manner via N-glycosylation. An emphasis has been placed on the C–N-glycosidic bond constructed during the formation of the nucleoside analogue. The third focus is on the separation of enantiomers of 1,3-oxathiolane nucleosides via resolution methods. The chemical as well as enzymatic procedures are reviewed and segregated in this review for effective synthesis of 1,3-oxathiolane nucleoside analogues.

中文翻译：

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1,3-氧杂硫杂环戊烷核苷类似物的合成策略

糖修饰的核苷在科学界引起了相当大的关注，无论是用作分子探针还是用作治疗剂。当核糖环的亚甲基在 3' 位被硫原子取代时，这些化合物已被证明是结构上有效的核苷类似物，最好的例子是 BCH-189。大多数方法传统上涉及核苷结构的化学修饰。它需要创建人工糖，并伴随着通过 N-糖基化偶联核碱基。然而，在过去的 30 年里，人们努力通过 C-1 处碳水化合物前体的选择性 N-糖基化来合成 1,3-氧杂硫杂环戊烷核苷，这种方法已成为一种强大的替代方法，可以进行简单的修饰。本综述旨在全面概述文献中报道的获取 1,3-氧杂硫杂环戊烷核苷的方法。本综述的第一个重点是从不同的起始材料构建 1,3-氧杂硫戊环。第二个重点涉及 1,3-氧杂硫杂环戊二烯环与不同核碱基的偶联方式，即通过 N-糖基化以立体选择性方式仅产生一种异构体。重点是在核苷类似物形成过程中构建的 C-N-糖苷键。第三个重点是通过拆分方法分离 1,3-氧杂硫杂环戊烷核苷的对映异构体。本次审查对化学和酶促程序进行了审查和分离，以有效合成 1,3-氧杂硫杂环戊烷核苷类似物。