Total Synthesis of (+)-Nankakurines A and B and (±)-5-<i>epi</i>-Nankakurine A
作者:Ryan A. Altman、Bradley L. Nilsson、Larry E. Overman、Javier Read de Alaniz、Jason M. Rohde、Veronique Taupin
DOI:10.1021/jo101619d
日期:2010.11.19
enone (+)-9 and diene 48 by a cationic Diels−Alder reaction. The Diels−Alder reactants were synthesized from 5-hexyn-1-ol (16) and (+)-pulegone (49), respectively. The tetracyclic ring system of 1 was generated using an unprecedented nitrogen-terminated aza-Prins cyclization cascade. The enantioselective total syntheses of (+)-nankakurine A (2) and (+)-nankakurine B (3) establish the relative and absolute
石松生物碱 (+)-nankakurine A ( 2 )、(+)-nankakurine B ( 3 ) 和最初声称的 nankakurine A结构1的首次全合成完成。2和3的合成具有苛刻的分子内偶氮甲亚胺环加成反应,这是生成八氢-3,5-乙醇喹啉部分并在螺哌啶环接点处安装正确相对构型的关键步骤。环化前驱体由八氢萘酮50制备,由烯酮(+)- 9和二烯48组装而成。通过阳离子 Diels-Alder 反应。Diels-Alder 反应物分别由 5-hexyn-1-ol ( 16 ) 和 (+)-pulegone ( 49 )合成。的四环环系统1使用了前所未有的氮封端的氮杂环化的Prins级联生成。(+)-nankakurine A ( 2 ) 和 (+)-nankakurine B ( 3 )的对映选择性全合成确定了这些生物碱的相对和绝对构型,并且足够简洁,大量的2和3为生物学研究做准备。(+)-Nankakurine
Formation of radicals by irradiation of alkyl halides in the presence of triethylamine. Application to the synthesis of (±)-bisabolangelone
The irradiation of unsaturated halides in the presence of triethylamine leads to the formation of the corresponding cyclized products. This photoreductive cyclization has been used to synthesize the bicyclic core of (±)-bisabolangelone.