Complementary enantioselective routes to the quinolizidine alkaloids lupinine and epilupinine
作者:Christopher Morley、David W. Knight、Andrew C. Share
DOI:10.1016/s0957-4166(00)82366-6
日期:1990.1
into a chiral 2-piperidineacetate has been effected both by enolate Claisen rearrangement of an allyl ester and by direct allylation of the intermediate lithium enolate [(7) → (8) + (9)] (Scheme 1). These two approaches give largely the opposite stereochemistry at the newly created centre; subsequent hydroboration and cyclisation of ester (9) leads to (+)-lupinine (12).
将α-2-[丙烯基]取代基引入手性2-哌啶乙酸酯中既可以通过烯丙基酯的烯醇酸克莱森重排,也可以通过中间烯醇酸锂的直接烯丙基化来实现[(7)→(8)+(9) ](方案1)。在新创建的中心,这两种方法在很大程度上产生了相反的立体化学。随后酯(9)的硼氢化和环化反应生成(+)-羽扇豆碱(12)。