Enantioselective Total Synthesis of (−)-Walsucochin B
摘要:
The first enantioselective total synthesis of the structurally unique nortriterpenoid (-)-walsucochin B has been accomplished through the cationic polyolefin cyclization initiated by chiral epoxide. The core framework and the stereocenters in the natural product were all constructed in this step. A site-selective, late-stage free-radical halogenation and Seyferth-Gilbert homologation was adopted to install the acetylene moiety to synthesize the phenylacetylene. The absolute configuration of walsucochin B was confirmed through enantioselective total synthesis.
Total Synthesis of Antiproliferative Parvifloron F
作者:Yohei Saito、Masuo Goto、Kyoko Nakagawa-Goto
DOI:10.1021/acs.orglett.7b03763
日期:2018.2.2
first total synthesis of parvifloron F, a bioactive highly oxidized abietane diterpene, was achieved. The abietane skeleton was constructed by Lewis acid promoted cyclization. Preliminary structure–activityrelationship correlations were established for the synthetic intermediates against human tumor cell lines. Certain compounds showed unique selective antiproliferative activityagainst triple-negative
Synthesis of a Dicyano Abietane, a Key Intermediate for the Anti-inflammatory Agent TBE-31
作者:Evans O. Onyango、Liangfeng Fu、Gordon W. Gribble
DOI:10.1021/ol403289y
日期:2014.1.3
The synthesis of dicyano abietane 11, a potentialprecursor to the biologically active tricyclic bis-cyano enone 6 (TBE-31), was accomplished in eight steps from epoxide 13. The synthesis features a Lewis acid promoted stereoselective cyclization of epoxide 13 to generate the tricyclic ring system 12 in one step.
A New Strategy for Stereocontrol of Cation−Olefin Cyclization. The First Chemical Emulation of the A/B-<i>trans</i>-9,10-<i>syn</i>-Folding Pathway of Steroid Biosynthesis from 2,3-Oxidosqualene