This account describes an overview of the asymmetric syntheses of pyrrolizidines, indolizidines and quinolizidines via a common double reductive cyclisation protocol. The highly diastereoselective conjugate addition of an enantiopure lithium amide to an α,β-unsaturated ester incorporating a terminal C=C bond installed the nitrogen-bearing stereogenic centre and was followed by enolate functionalisation to introduce the second olefinic functionality. Alternatively, conjugate addition to the corresponding α-alkenyl α,β-unsaturated ester followed by α-protonation of the intermediate enolate may also be used to access the cyclisation precursor. After oxidation of the two terminal olefinic units to give the corresponding dialdehyde, tandem hydrogenolysis/hydrogenation was employed to efficiently construct the azabicyclic core of each target molecule. This double reductive cyclisation strategy was successfully utilised in the syntheses of 13 azabicyclic alkaloids or closely related analogues. 1 Introduction 2 Asymmetric Syntheses of (–)-Isoretronecanol and (–)-Trachelanthamidine 3 Asymmetric Syntheses of (+)-Trachelanthamidine [(+)-Laburnine], (+)-Tashiromine and (+)-epi-Lupinine 4 Asymmetric Syntheses of (–)-Hastanecine, (–)-Turneforcidine and (–)-Platynecine 5 Asymmetric Syntheses of (–)-Macronecine, (–)-Petasinecine, (–)-1-epi-Macronecine, (+)-1-epi-Petasinecine and (+)-2-epi-Rosmarinecine 6 Conclusion

中文翻译：

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通过双还原环化方案不对称合成吡咯里西啶、吲哚里西啶和喹诺里西啶

该帐户描述了通过常见的双还原环化协议不对称合成吡咯里西啶、吲哚里西啶和喹尼西啶的概述。高度非对映选择性共轭加成对映纯氨基锂到α，β-不饱和酯并结合末端C=C键安装含氮立体中心，然后烯醇官能化以引入第二个烯烃官能团。或者，也可以使用与相应的α-烯基α，β-不饱和酯的共轭加成，随后中间体烯醇化物的α-质子化来获得环化前体。在两个末端烯烃单元氧化得到相应的二醛后，采用串联氢解/氢化来有效构建每个目标分子的氮杂双环核心。这种双还原环化策略已成功用于合成 13 种氮杂双环生物碱或密切相关的类似物。1 引言 2 (–)-异戊二烯醇和 (–)-Trachelanthamidine 的不对称合成 3 (+)-Trachelanthamidine [(+)-Laburnine]、(+)-Tashiromine 和 (+)-epi-Lupinine 的不对称合成 4 不对称合成(-)-Hastanecine、(-)-Turneforcidine 和 (-)-Platynecine 的 5 不对称合成 (-)-Macronecine、(-)-Petasinecine、(-)-1-epi-Macronecine、(+)-1- Epi-Petasinecine 和 (+)-2-epi-Rosmarinecine 6 结论