Concise Enantioselective Synthesis of 3,5-Dialkyl-Substituted Indolizidine Alkaloids via Sequential Cross-Metathesis−Double-Reductive Cyclization
作者:Stefan Randl、Siegfried Blechert
DOI:10.1021/jo0346095
日期:2003.11.1
5-dialkyl-substituted indolizidine alkaloids is reported. The convergent syntheses are based on a novel sequence of a cross-metathesis (CM) reaction of an alpha,beta-unsaturated ketone and a chiral homoallylic amine followed by a domino reaction involving hydrogenation, N-deprotection, and two diastereoselective reductive aminations. Our concept presents one of a few examples of a highly selective CM reaction in
报道了两个3,5-二烷基取代的吲哚并立定生物碱的有效立体选择性合成。收敛合成基于α,β-不饱和酮和手性均烯丙基胺的交叉复分解(CM)反应的新序列,然后是涉及氢化,N-脱保护和两个非对映选择性还原胺化的多米诺反应。我们的概念提供了天然产物合成中高选择性CM反应的几个例子之一。