The 3a-hydroxyhexahydropyrrolo[2,3-b]indole-2-carboxylic acid (HPIC) residue and its aza-analogue are found in many bioactive natural products. In this account, short divergent total syntheses of several such natural products, diastereomers and analogues are described. It is demonstrated that by appropriate combination of different efficient tactics such as biomimetic/bio-inspired synthesis, chemo/regioselective reactions, umpolung of regioselectivity and/or reactivity, and tandem reactions, the enantioselective syntheses of polycyclic molecules such as (+)-asperlicin E and (–)-robustanoids A and B can be achieved in a protecting-group-free and redox-economical manner, in only three to four steps starting from l -tryptophan. 1 Introduction 2 Strategic Considerations 2.1 Occurrence of HO-HPIC and HO-aza-HPIC Residues in Natural Products 2.2 Biosyntheses of HO-HPIC and HO-aza-HPIC Residues 2.3 Chemical Syntheses of HO-HPIC and HO-aza-HPIC Residues 3 Procedure-Economical Syntheses of HO-HPIC-Containing Natural Products 3.1 Protecting-Group-Free Syntheses of Asperlicin E, Its Diastereomer, and an Analogue 3.2 Divergent Syntheses of (–)-Robustanoids A and B, a Diastereomer, and Analogues 4 Conclusion and Future Perspectives

中文翻译：

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含有 3a-羟基六氢吡咯并[2,3-b]吲哚-2-羧酸残基的多环天然产物和类似物的经济、对映选择性全合成

3a-羟基六氢吡咯并 [2,3-b] 吲哚-2-羧酸 (HPIC) 残基及其氮杂类似物存在于许多具有生物活性的天然产品中。在这个帐户中，描述了几种此类天然产物、非对映异构体和类似物的短发散全合成。结果表明，通过不同有效策略的适当组合，如仿生/仿生合成、化学/区域选择性反应、区域选择性和/或反应性的umpolung，以及串联反应，多环分子如（+）-天冬氨酸的对映选择性合成E 和 (-)-robustanoids A 和 B 可以以无保护基团和氧化还原经济的方式实现，从 l-色氨酸开始只需三到四个步骤。1 引言 2 战略考虑 2.1 HO-HPIC 和 HO-aza-HPIC 残留在天然产物中的出现 2.