描述了适用于快速制备大量不同结构的番红霉素 A 类似物的 10 步固体支持的对映选择性合成。合成路线类似于固相肽合成,涉及 N-保护的 α-氨基醛反应物的定向缩合。开发了一种新型双接头,用于通过 C-保护基团(一种取代的吗啉代腈衍生物)将中间体连接到固体支持物上。该路线采用了一种新型的非对映特异性环释放机制,支持番红霉素核心中多个位点的结构变异,并且无需对产品或任何中间体进行色谱纯化。为了证明在多个地点进行结构变异的可行性,16 种番红霉素 A 类似物的基质是通过平行合成制备的,同时改变两个位点。这项工作不仅是大规模图书馆建设的初步步骤,而且还是在固相上使用连续立体选择性 CC 键形成反应制备天然产物类似物的一个例子。
A convergent synthesis of (4R,15R,16R,21S)-rollicosin (1) and (4R,15S,16S,21S)-rollicosin (2) was accomplished. Hydroxy lactone 6a and/or 6b were synthesized from 4-pentyn-1-ol, and α,β-unsaturated lactone 7 was synthesized from γ-lactone 8 and 5-hexen-1-ol. Inhibitory activity of these compounds was examined with bovine heart mitochondrial complex I.
Total Synthesis of the Originally Proposed and Revised Structures of Palmerolide A and Isomers Thereof
作者:K. C. Nicolaou、Ya-Ping Sun、Ramakrishna Guduru、Biswadip Banerji、David Y.-K. Chen
DOI:10.1021/ja710485n
日期:2008.3.1
Palmerolide A is a recently disclosed marine natural product possessing striking biological properties, including potent and selective activity against the melanoma cancer cell line UACC-62. The total syntheses of five palmerolide A stereoisomers, including the originallyproposed (1) and the revised [ent-(19-epi-20-epi-1)] structures, have been accomplished. The highly convergent and flexible strategy
Synthetic studies toward the brasilinolides: controlled assembly of a protected C1–C38 polyol based on fragment union by complex aldol reactions
作者:Ian Paterson、Michael P. Housden、Christopher J. Cordier、Paul M. Burton、Friedrich A. Mühlthau、Olivier Loiseleur
DOI:10.1039/c5ob00498e
日期:——
performed in a complex boron-mediated aldolreaction to install the required C19 hydroxyl stereocentre when alternative Mukaiyama-type aldol protocols proved unrewarding. A protected C1–C38 polyol 93 was subsequently prepared, setting the stage for future late-stage diversification toward the various brasilinolide congeners. Throughout this work, asymmetric boron-mediated aldolreactions of chiral ketones