General strategies for the synthesis of the major classes of C-aryl glycosides
General strategies for the synthesis of the major classes of C-aryl glycosides
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DOI：
10.1021/ja0108640
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发表时间：
2001-07-18
影响因子：
15
通讯作者：
Martin, SF
中科院分区：
文献类型：
--
作者：
Kaelin, DE;Lopez, OD;Martin, SF
C-芳基糖苷类抗生素，如Kidamycin（1），是一类重要的具有生物活性的天然产物。[1]虽然kidamycin代表该家族的一个亚组的成员，但C-芳基糖苷有四种常见的结构类型（第I-IV组），根据芳环上糖残基和羟基的取代模式进行分类。因此，这些复杂抗生素所带来的重大挑战之一在于设计和开发用于合成该家族的四个主要亚组的统一策略。3，4在考虑了许多新的方法C-芳基糖苷，我们被吸引到两个途径，总结在方案1。众所周知，与2相关的化合物（通过呋喃和苯炔的环加成形成）的酸催化重排产生萘酚（路径A）。5然而，C-呋喃基糖苷从未在此类方法中用作二烯。作为经由路径B引入第二糖残基的先例，相关的是经由与碳负离子的SN 2 ′反应和经由与芳基碘的钯催化反应打开氧杂双环化合物2，得到
The C-aryl glycoside antibiotics, as exemplified by kidamycin (1), constitute an important class of biologically active natural products. 1 While kidamycin represents a member of one subgroup of this family, there are four common structural types of C-aryl glycosides (Groups I-IV), which have been classified on the basis of the substitution pattern of the sugar residue (s) and the hydroxyl group (s) on the aromatic ring. 2 Hence, one of the significant challenges presented by these complex antibiotics lies in the design and development of a unified strategy for the synthesis of the four major subgroups of this family. 3, 4After considering a number of novel approaches to C-aryl glycosides, we were attracted to the two pathways that are summarized in Scheme 1. The acid-catalyzed rearrangement of compounds related to 2, which are formed by cycloadditions of furans and benzynes, was well-known to give naphthols (Path A). 5 However, C-furyl glycosides have never been employed as dienes in such processes. As a precedent for the introduction of a second sugar residue via Path B, it is relevant that opening of oxabicyclic compounds 2 via an SN2′ reaction with carbanions and via a palladium-catalyzed reaction with aryl iodides to give