Enantiospecific Synthesis of Annulated Nicotine Analogues from <scp>d</scp>- and <scp>l</scp>-Glutamic Acid. Pyridotropanes
作者:Sean C. Turner、Hongbin Zhai、Henry Rapoport
DOI:10.1021/jo991609p
日期:2000.2.1
The conformationally restricted nicotinoid 1-methyl-8-azabicyclo[3.2.1]octano[2,3-c]pyridine, pyrido[3,4-b]tropane, has been prepared enantiospecifically from both d- and l-glutamic acid. The method involved coupling of pyroglutamic acid derivatives with ortho-lithiated 4-chloropyridine, followed by intramolecular imine formation and reduction to generate the d- and l-5-substituted proline esters.
构象受限的类烟碱 1-methyl-8-azabicyclo[3.2.1]octano[2,3-c]pyridine, pyrido[3,4-b]tropane 是由 d- 和 l- 谷氨酸制备的。该方法涉及将焦谷氨酸衍生物与邻位锂化的 4-氯吡啶偶联,然后形成分子内亚胺并还原生成 d-和 l-5-取代的脯氨酸酯。氯碘交换和侧链延伸为 [3.2.1] 系统提供了前体。8-氮杂双环[3.2.1]辛基-[2,3-c]吡啶骨架的构建是通过分子内Heck反应实现的。随后的臭氧分解产生的酮被还原为甲醇或亚甲基,产生融合的尼古丁类似物。