The first total synthesis of 5′-O-α-d-glucopyranosyl tubercidin was successfully developed. It is a structurally unique disaccharide 7-deazapurine nucleoside exhibiting fungicidal activity, and was isolated from blue-green algae. The total synthesis was accomplished in eight steps with 27% overall yield from commercially available 1-O-acetyl-2,3,5-tri-O-benzoyl-β-d-ribose. The key step involves stereoselective α-O-glycosylation of the corresponding 7-bromo-6-chloro-2′,3′-O-isopropylidene-β-d-tubercidin with 2,3,4,6-tetra-O-benzyl-glucopyranosyl trichloroacetimidate. All spectra are in accordance with the reported data for natural 5′-O-α-d-glucopyranosyl tubercidin. Meanwhile, 5′-O-β-d-glucopyranosyl tubercidin was also prepared using the same strategy.

中文翻译：

---

5'-O-α-d-吡喃葡萄糖基结核菌素的首次全合成。

首次全合成5′- O -α- d-吡喃葡萄糖基结核菌素研制成功。它是一种结构独特的二糖 7-脱氮嘌呤核苷，具有杀菌活性，是从蓝绿藻中分离出来的。整个合成分八步完成，市售的 1- O-乙酰基-2,3,5-三-O-苯甲酰基-β- d-核糖总产率为 27%。关键步骤涉及相应的7-溴-6-氯-2',3'- O-异亚丙基-β- d-结核菌素与2,3,4,6-四-O-苄基的立体选择性α- O-糖基化-吡喃葡萄糖基三氯乙酰亚胺酯。所有光谱均符合天然 5'- O -α- d-吡喃葡萄糖基结核菌素的报告数据。同时，采用同样的策略也制备了5'- O -β- d-吡喃葡萄糖基结核菌素。