Intramolecular Carbolithiation Reactions for the Preparation of Azabicyclo[2.2.1]heptanes
作者:Iain Coldham、Joan-Carles Fernàndez、Kathy N. Price、David J. Snowden
DOI:10.1021/jo000088z
日期:2000.6.1
1]heptane ring system is accessed from either diastereomer of a 2,5-disubstituted pyrrolidine, via a chiral organolithium intermediate. The 2-azabicyclo[2.2.1]heptane ring system is formed stereoselectively in low yield by a tandem cyclization, together with the product from monocyclization. Better yields of the 2-aza ring system can be obtained using an alternative approach from a 2-tributylstannyl-4-allylpyrrolidine
锡-锂交换和分子内碳锂化(阴离子环化)已被用于构建氮杂双环[2.2.1]庚烷环系统的三个氮-位置异构体。7-氮杂双环[2.2.1]庚烷环系通过手性有机锂中间体从2,5-二取代的吡咯烷的任一非对映异构体获得。2-氮杂双环[2.2.1]庚烷环系统是通过串联环化与单环化产物一起以低产率立体选择性地形成的。尽管锡(以及锂)原子和烯丙基单元的反式排列,也可以使用另一种方法从2-三丁基锡烷基-4-烯丙基吡咯烷中获得更好的2-氮杂环系统产率。1-氮杂双环[2.2.1]庚烷环系统距离4-哌啶酮仅三步。