Improved synthesis of the polyhydroxylated central part of phoslactomycin B
Improved synthesis of the polyhydroxylated central part of phoslactomycin B
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DOI：
10.1016/j.tetlet.2007.06.058
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发表时间：
2007-08-06
影响因子：
1.8
通讯作者：
Kobayashi, Yuichi
中科院分区：
文献类型：
--
作者：
Nonaka, Hisato;Maeda, Noriaki;Kobayashi, Yuichi
研究了合成磷乳霉素 B 的 C(7)-C(13) 中间体的新方法。 β,γ-不饱和酯的不对称二羟基化反应顺利进行，得到 ee 含量为 97.6% 的 β-羟基-γ-内酯，将其保护为 PMB 醚，然后进行氢化物还原，得到二醇。在选择性保护 prim-OH 后，氧化 see-OH 并通过螯合控制添加 CH2=CHMgBr，得到 C(7)-C(11) 链段。随后，利用Noyori催化剂通过不对称转移氢化构建了C(11)立构中心。 (c) 2007 Elsevier Ltd. 保留所有权利。
A new approach to the C(7)-C(13) intermediate for the synthesis of phoslactomycin B was investigated. Asymmetric dihydroxylation of the beta,gamma-unsaturated ester proceeded cleanly to afford the beta-hydroxyl-gamma-lactone with 97.6% ee, which upon protection as the PMB ether followed by hydride reduction furnished a diol. After selective protection of the prim-OH, oxidation of the see-OH and chelation-controlled addition of CH2=CHMgBr afforded the C(7)-C(11) segment. Later on, the C(11) stereocentre was constructed by the asymmetric transfer hydrogenation using the Noyori catalyst. (c) 2007 Elsevier Ltd. All rights reserved.