作者:Mirko Zaja、Siegfried Blechert
DOI:10.1016/j.tet.2004.06.145
日期:2004.10
An enantioselective synthesis of the quinolizidine alkaloid (−)-lasubine II 1 is reported. Two different pathways to the key intermediate 2 are described. The first case involving a sequence of ring rearrangement metathesis (RRM), simple functional group interconversion operations, followed by a stereoselective cross metathesis (CM) and in the second case a domino ring opening-/ring closing-/cross
报道了喹喔啉生物碱(-)-lasubine II 1的对映选择性合成。描述了通往关键中间体2的两种不同途径。第一种情况涉及环重排复分解(RRM)的序列,简单的官能团互转换操作,然后是立体选择性交叉复分解(CM),第二种情况涉及多米诺环的开环/闭环/交叉复分解步骤。在两种情况下,在易位反应之后,仅获得E-异构体。通过分子内迈克尔反应实现了对喹唑烷骨架的最终环化。该概念代表了天然产物合成中高度立体选择性的RRM-CM组合的第一个例子。