文献类型：期刊文献

英文题名：Construction of the Isocopalane Skeleton: Application of a Desulfinylative 1,7-Hydrogen Atom Transfer Strategy

作者：Xiao, Xiong[1];Xu, ZhongYu[1];Zeng, Qian-Ding[4];Chen, Xi-Bo[1];Ji, Wen-Hao[1];Han, Ying[4];Wu, PeiYing[3];Ren, Jiangmeng[1];Zeng, Bu-Bing[1,2]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab New Drug Design, Sch Pharm, Shanghai 200237, Peoples R China;[2]Chinese Acad Sci, Shanghai Inst Organ Chem, Key Lab Synthet Chem Nat Subst, Shanghai 200032, Peoples R China;[3]Shanghai Univ Tradit Chinese Med, Sch Pharm, Shanghai 201203, Peoples R China;[4]Yangzhou Univ, Coll Chem & Chem Engn, Yangzhou 225002, Jiangsu, Peoples R China

年份：2015

卷号：21

期号：23

起止页码：8351

外文期刊名：CHEMISTRY-A EUROPEAN JOURNAL

收录：;EI(收录号：20152200889604);WOS:【SCI-EXPANDED(收录号:WOS:000355260000006)，CCR-EXPANDED(收录号:WOS:000355260000006)】；

基金：This work was financially supported by National Natural Science Foundation of China (21302053), Science and Technology Commission of Shanghai Municipality (14DZ1900102) and the Fundamental Research Funds for the Central University (WY1113007).

语种：英文

外文关键词：hydrogen transfer; natural products; persulfates; synthons; terpenoids

摘要：Two attractive chirons, aldehyde 6 and chloride 7, exhibiting functionalized ent-spongiane-type tricyclic skeletons (ABC ring system), have been constructed and their absolute configurations have been studied by NMR spectroscopy and confirmed by single-crystal X-ray diffraction. Both of these chirons are derived from commercially available andrographolide in good yield. Aldehyde 6 is obtained through a novel K2S2O8-catalyzed aquatic ring-closing reaction of allylic sodium sulfonate and intramolecular 1,7-hydrogen atom transfer process. Further mechanistic investigations demonstrate that the 1,7-hydrogen atom transfer is a free-radical process, whereby hydrogen migrates from C18 to C17, as evidenced by double-18- deuterium-labeled isotope experiments. Prospective applications of these two chiral sources are also discussed.