The structure of intermediate products of ‘fragmentation’ of 10-bromodihydrocinchonine
作者:Jacek Thiel、Piotr Fiedorow
DOI:10.1016/s0022-2860(97)00265-2
日期:1998.1
Abstract 10-Bromodihydrocinchonine 1d , similarly to analogical derivatives of other main cinchona alkaloids, transforms into nicinquine and isonicinquine 2d formally loosing its C2 carbon atom in a form of formaldehyde. This reaction was found to proceed via the so-far unstudied intermediate compounds ( 5a ) 4- S -( Z -propenyl)- and ( 5 4- S -( E -propenyl)-6- R -7- S -(quinolyl-4)-8-oxa-1- R -azabicyclo[4
摘要 10-溴二氢辛可宁 1d 与其他主要金鸡纳生物碱的类似衍生物类似,可转变成尼辛喹和异尼克奎宁 2d 以甲醛的形式失去其 C2 碳原子。发现该反应通过迄今为止尚未研究的中间体化合物 (5a) 4- S -( Z -丙烯基)- 和 ( 5 4- S -( E -丙烯基)-6- R -7- S -(喹啉基) -4)-8-oxa-1-R-氮杂双环[4.3.0]壬烷,它同时是母体辛可宁的新型重排产物。这些化合物的立体结构主要使用核磁共振技术测定。分子力学计算支持构象异构体 5 和 5a 的能量最小值。讨论了 1d → 5 → 2d 序列的机制。生物碱 5 在空间上优于其 Z 异构体。