Synthesis and reactivity of 4'-deoxypentenosyl disaccharides.
Synthesis and reactivity of 4'-deoxypentenosyl disaccharides.
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4-脱氧戊烯基二糖的合成和反应性。
DOI：
10.1021/jo500449h
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Wei,Alexander
中科院分区：
文献类型：
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作者：
Padungros,Panuwat;Fan,Ren-Hua;Casselman,MatthewD;Cheng,Gang;Khatri,HariR;Wei,Alexander
4-脱氧戊烯糖苷（4-DP）是稀有或更高阶吡喃糖苷的多功能化合物，它们为C5位置的结构多样化提供了入口。以前的研究表明，4-DP进行立体控制的DMDO氧化;随后的环氧开环与各种亲核试剂可以进行对映或顺式选择性。本文报道了α-和β-连接的4′-脱氧戊烯基（4′-DP）二糖的合成，并利用DMDO氧化/开环序列研究了其糖基化后的C5′加成。α-连接的4′-DP二糖是通过BSP/Tf 2 O活化法将噻吩基4-DP供体与糖基受体偶联得到的，而β-连接的4′-DP二糖是通过微波条件下葡萄糖醛酸基二糖的脱羧消除得到的。α-和β-连接的4′-DP二糖都可以用DMDO高立体选择性地环氧化。在某些情况下，α-环氧戊烯糖苷可以通过2-呋喃基溴化锌的合成成功地转化为末端艾杜糖醛酸。这些研究支持了一种新的寡糖合成方法，其中末端4′-DP单元的立体化学构型在后糖基化阶段建立。
4-Deoxypentenosides (4-DPs) are versatile synthons for rare or higher-order pyranosides, and they provide an entry for structural diversification at the C5 position. Previous studies have shown that 4-DPs undergo stereocontrolled DMDO oxidation; subsequent epoxide ring-openings with various nucleophiles can proceed with bothantiorsynselectivity. Here, we report the synthesis of α- and β-linked 4′-deoxypentenosyl (4′-DP) disaccharides, and we investigate their post-glycosylational C5′ additions using the DMDO oxidation/ring-opening sequence. The α-linked 4′-DP disaccharides were synthesized by coupling thiophenyl 4-DP donors with glycosyl acceptors using BSP/Tf2O activation, whereas β-linked 4′-DP disaccharides were generated by the decarboxylative elimination of glucuronyl disaccharides under microwave conditions. Both α- and β-linked 4′-DP disaccharides could be epoxidized with high stereoselectivity using DMDO. In some cases, the α-epoxypentenosides could be successfully converted into terminall-iduronic acids via thesynaddition of 2-furylzinc bromide. These studies support a novel approach to oligosaccharide synthesis, in which the stereochemical configuration of the terminal 4′-DP unit is established at a post-glycosylative stage.