Systemic Study on the Biogenic Pathways of Yezo’otogirins: Total Synthesis and Antitumor Activities of (±)-Yezo’otogirin C and Its Structural Analogues
摘要:
A systematic study of the biomimetic pathways to yezo'otogirin C under aerobic and anaerobic conditions has been investigated, and both are found to be feasible pathways to the natural product depending on the physiological conditions. Because of the lower activation energy, the aerobic process would be more favorable when the in vivo oxygen level is high. In the course of this study, a highly efficient synthetic route to (+/-)-yezo'otogirin C has been established in four steps (31% overall yield) from a readily available compound without using any protecting groups. The natural product and its structural analogues exhibited antitumor activities against several human cancer cell lines and appeared to arrest cell cycles in different phases.
The unexpected formation of a 4-hydroxytetrahydroquinolin-2(1H)-onefrom a bicyclo[3.3.1]nonanetrione system and an amino alcohol in the presence of TsOH is reported. The mechanism of this transformation was studied by DFT calculations. The reaction provides an entry to the synthesis of highly functionalized 4-hydroxytetrahydroquinolin-2(1H)-ones.
of photoredox-catalyzed cascade reactions using diaryliodoniumsalts for the concise synthesis of norascyronone A and β-eudesmol. A rationally designed photoredox-catalyzed arylation/cyclization/Friedel–Crafts cascade reaction of enone was exploited to generate the norascyronone polycyclic skeleton. A visible-light-induced radical cyclization/acyloxy-migration reaction was explored to forge the decalin
在此,我们开发了两种类型的光氧化还原催化级联反应,使用二芳基碘鎓盐来简明合成去甲环龙 A 和 β-eudesmol。利用合理设计的光氧化还原催化的烯酮芳基化/环化/Friedel-Crafts 级联反应生成去甲环芳酮多环骨架。探索了一种可见光诱导的自由基环化/酰氧基迁移反应来构建eudesmol的萘烷骨架,并且机理研究表明该反应是由烯醇酯的单电子氧化引发的。
Progress toward the Synthesis of Garsubellin A and Related Phloroglucins: The Direct Diastereoselective Synthesis of the Bicyclo[3.3.1]nonane Core
作者:Sarah J. Spessard、Brian M. Stoltz
DOI:10.1021/ol025968+
日期:2002.5.1
[reaction: see text] A highly diastereoselective single-step cyclization reaction provides access to the bicyclo[3.3.1]nonane core of the polyprenylated phloroglucin natural product garsubellin A. Further elaboration to a more functionalized analogue involves a sequential Claisen rearrangement/Grubbs olefin cross-metathesis strategy. Additionally, this strategy was extended to the preparation of the