Asymmetric total synthesis of (+)-equilenin utilizing two types of cascade ring expansion reactions of small ring systems

2000 ◽  
pp. 2629-2635 ◽  
Author(s):  
Masahiro Yoshida ◽  
Mohamed Abdel-Hamid Ismail ◽  
Hideo Nemoto ◽  
Masataka Ihara
Keyword(s):  
Total Synthesis ◽  
Ring Expansion ◽  
Small Ring ◽  
Asymmetric Total Synthesis ◽  
Ring Systems

Total Synthesis of (–)-Alstofolinine A: Selected Furan Oxidation/ Cyclization Cascade

Synlett ◽  
2019 ◽  
Vol 31 (01) ◽  
pp. 7-12 ◽  
Author(s):  
Ye Zhang ◽  
Lei Zhang ◽  
Xiangbing Qi
Keyword(s):  
Total Synthesis ◽  
Common Core ◽  
Nucleophilic Addition ◽  
Addition Reaction ◽  
Indole Alkaloids ◽  
Indole Alkaloid ◽  
Asymmetric Total Synthesis ◽  
Ring Systems ◽  
Synthetic Strategy ◽  
Nucleophilic Addition Reaction

Indole-fused tetracyclic ring systems containing nitrogen atoms are common core skeletons of many indole alkaloids such as sarpagine, macroline, and ajmaline. Efficient and stereoselective construction of these ring systems can promote the development of the corresponding alkaloid syntheses. In this article, we briefly summarize our current progress toward the application of the aza-Achmatowicz reaction and indole nucleophilic addition reaction cascade for the first asymmetric total synthesis of the macroline-type indole alkaloid (–)-Alstofolinine A. Our synthetic strategy is based on furan oxidation/rearrangement and proceeds from easily accessible materials such as indole and furan derivatives.

scholarly journals Facile generation of bridged medium-sized polycyclic systems by rhodium-catalysed intramolecular (3+2) dipolar cycloadditions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bao-Long Hou ◽  
Jonathan J. Wong ◽  
Na Lv ◽  
Yong-Qiang Wang ◽  
K. N. Houk ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Single Step ◽  
Bioactive Molecules ◽  
Dipolar Cycloaddition ◽  
General Strategy ◽  
Diastereoselective Synthesis ◽  
Asymmetric Total Synthesis ◽  
Ring Systems ◽  
Dipolar Cycloadditions ◽  
Unusual Type

AbstractBridged medium-sized bicyclo[m.n.2] ring systems are common in natural products and potent pharmaceuticals, and pose a great synthetic challenge. Chemistry for making bicyclo[m.n.2] ring systems remains underdeveloped. Currently, there are no general reactions available for the single-step synthesis of various bridged bicyclo[m.n.2] ring systems from acyclic precursors. Here, we report an unusual type II intramolecular (3+2) dipolar cycloaddition strategy for the syntheses of various bridged bicyclo[m.n.2] ring systems. This rhodium-catalysed cascade reaction provides a relatively general strategy for the direct and efficient regioselective and diastereoselective synthesis of highly functionalized and synthetically challenging bridged medium-sized polycyclic systems. Asymmetric total synthesis of nakafuran-8 was accomplished using this method as a key step. Quantum mechanical calculations demonstrate the mechanism of this transformation and the origins of its multiple selectivities. This reaction will inspire the design of the strategies to make complex bioactive molecules with bridged medium-sized polycyclic systems.

ChemInform Abstract: Asymmetric Total Synthesis of (+)-Equilenin Utilizing Two Types of Cascade Ring Expansion Reactions of Small Systems.

ChemInform ◽  
2000 ◽  
Vol 31 (51) ◽  
pp. no-no
Author(s):  
Masahiro Yoshida ◽  
Mohamed Abdel-Hamid Ismail ◽  
Hideo Nemoto ◽  
Masataka Ihara
Keyword(s):  
Total Synthesis ◽  
Ring Expansion ◽  
Asymmetric Total Synthesis ◽  
Small Systems

The Asymmetric Synthesis of Fused Cyclopentenone Ring Systems: A formal asymmetric total synthesis of (?)-isocomene

1996 ◽  
Vol 79 (4) ◽  
pp. 1026-1046 ◽  
Author(s):  
Albert I. Meyers ◽  
Stefan Bienz ◽  
Hyok-Boong Kwon ◽  
Richard H. Wallace
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Asymmetric Total Synthesis ◽  
Ring Systems
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