A palladium-catalyzed glycosylation reaction: The de novo synthesis of natural and unnatural glycosides
A palladium-catalyzed glycosylation reaction: The de novo synthesis of natural and unnatural glycosides
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DOI：
10.1021/ja037097k
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发表时间：
2003-10-15
影响因子：
15
通讯作者：
O'Doherty, GA
中科院分区：
文献类型：
--
作者：
Babu, RS;O'Doherty, GA
报道了多种醇的高度立体选择性和立体特异性的钯催化糖基化反应。该反应选择性地将α-2-取代的6-羧基-2H-吡喃-3(6H)-酮转化为α-2-取代的6-烷氧基-2H-吡喃-3(6H)-酮，并完全保留构型，并且类似地将具有β-羧基的吡喃酮转化为具有β-烷氧基的吡喃酮。该反应对于氨基酸醇和碳水化合物醇都同样有效。为了证明该过程在碳水化合物化学中的实用性，通过另外两个步骤将几种产品选择性地转化为 α-甘露糖吡喃糖苷。由于2-取代的6-羧基-2H-吡喃-3(6H)-酮是通过不对称合成制备的，因此该反应可用于制备双-或1-吡喃酮。
A highly stereoselective and sterospecific palladium-catalyzed glycosylation reaction of a variety of alcohols is reported. The reaction selectively converts α-2-substituted 6-carboxy-2H-pyran-3(6H)-ones into α-2-substituted 6-alkoxy-2H-pyran-3(6H)-ones with complete retention of configuration and similarly converts the pyranones with β-carboxy groups into pyranones with β-alkoxy groups. The reaction works equally well with both amino acid- and carbohydrate-based alcohols. To demonstrate the utility of this process for carbohydrate chemistry several of the products were selectively converted into α-manno-pyranosides in two additional steps. Because the 2-substituted 6-carboxy-2H-pyran-3(6H)-ones are prepared by asymmetric synthesis, this reaction can be used for the preparation of eitherd- orl-pyranones.