Synlett 2020; 31(17): 1681-1690
DOI: 10.1055/s-0040-1707164
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© Georg Thieme Verlag Stuttgart · New York

Procedure-Economical, Enantioselective Total Syntheses of Polycyclic Natural Products and Analogues Containing a 3a-Hydroxyhexahydropyrrolo[2,3-b]indole-2-carboxylic Acid Residue

Pei-Qiang Huang
Department of Chemistry and Fujian Provincial Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. of China   Email: pqhuang@xmu.edu.cn
› Author Affiliations
The author is grateful for the financial support provided by the National Natural Science Foundation of China (Grant Nos. 21672176 and 21931010), the National Key R&D Program of China (Grant No. 2017YFA0207302), and the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) of the Ministry of Education.
Further Information

Publication History

Received: 08 May 2020

Accepted after revision: 21 May 2020

Publication Date:
25 June 2020 (online)


Dedicated to the memory of the late Professor Shao-Min Zhou for his contribution to electrochemistry.

Abstract

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