scholarly journals Studies on asymmetric total synthesis of (−)-β-hydrastine via a chiral epoxide ring-opening cascade cyclization strategy

RSC Advances ◽  
2020 ◽  
Vol 10 (32) ◽  
pp. 18953-18958
Author(s):  
Jihui Li ◽  
Tianxiao Wu ◽  
Xinjing Song ◽  
Yang Zheng ◽  
Jiaxin Meng ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Ring Opening ◽  
Enantioselective Synthesis ◽  
Epoxide Ring ◽  
Asymmetric Total Synthesis ◽  
Epoxide Ring Opening ◽  
Cascade Cyclization ◽  
The Core

Herein, both CF3COOH-catalyzed (86% ee) and KHMDS-catalyzed (78% ee) chiral epoxide ring-opening cascade cyclization to facile and enantioselective synthesis of the core phthalide tetrahydroisoquinoline scaffold of (−)-β-hydrastine are described.

Asymmetric total synthesis of cryptoconcatone I

2019 ◽  
Vol 17 (14) ◽  
pp. 3552-3566 ◽  
Author(s):  
Ranjan Kumar Acharyya ◽  
Pratik Pal ◽  
Shrestha Chatterjee ◽  
Samik Nanda
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Asymmetric Total Synthesis ◽  
Epoxide Ring Opening ◽  
Cascade Cyclization ◽  
Naturally Occurring

An efficient asymmetric total synthesis of naturally occurring γ-Z-butenolide cryptoconcatone I was achieved by employing substrate-directed reductive epoxide ring opening and late-stage “Pd–Cu” catalyzed cascade cyclization.

A protecting group free and scalable approach towards total synthesis of (−)-venlafaxine

RSC Advances ◽  
2014 ◽  
Vol 4 (28) ◽  
pp. 14468-14470 ◽  
Author(s):  
Subhash P. Chavan ◽  
Kailash P. Pawar ◽  
Sumanta Garai
Keyword(s):  
Total Synthesis ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Protecting Group ◽  
Asymmetric Total Synthesis ◽  
Epoxide Ring Opening ◽  
Key Steps

A protecting group free asymmetric total synthesis of (−)-venlafaxine is reported. The strategy employs Sharpless epoxidation and regio-selective epoxide ring opening by an in situ generated Gilman reagent as key steps. This paper reports a 53% overall yield in 6 steps for total synthesis of (−)-venlafaxine.

First total synthesis of the highly potent antitumor lactones 8-chlorogoniodiol and parvistone A: Exploiting a bioinspired late-stage epoxide ring-opening

2017 ◽  
Vol 28 (2) ◽  
pp. 246-249 ◽  
Author(s):  
Perla Ramesh ◽  
Yarram Narasimha Reddy ◽  
Thatikonda Narendar Reddy ◽  
Navuluri Srinivasu
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Epoxide Ring Opening

Total synthesis of the proposed structure of a polyketide from Phialomyces macrosporus

2015 ◽  
Vol 51 (17) ◽  
pp. 3586-3589 ◽  
Author(s):  
Hideki Abe ◽  
Satoko Itaya ◽  
Kei Sasaki ◽  
Toyoharu Kobayashi ◽  
Hisanaka Ito
Keyword(s):  
Total Synthesis ◽  
Ring Opening ◽  
Furan Ring ◽  
Epoxide Ring ◽  
Epoxide Ring Opening

Total synthesis of the proposed structure of a polyketide isolated from Phialomyces macrosporus was accomplished. This synthesis features chemoselective epoxidation, regioselective epoxide ring opening, chemo- and diastereoselective dihydroxylation, and vinylation of lactone accompanied by the formation of a furan ring.

Synthesis of trans N-Substituted Pyrrolidine Derivatives Bearing 1,2,4-triazole Ring

2021 ◽  
Vol 19 ◽  
Author(s):  
Tangella Nagendra Prasad ◽  
Yeruva Pavankumar Reddy ◽  
Poorna Chandrasekhar Settipalli ◽  
Vadiga Shanthi Kumar ◽  
Eeda Koti Reddy ◽  
...  
Keyword(s):  
Ring Opening ◽  
Biological Activities ◽  
Triazole Ring ◽  
Vital Role ◽  
Epoxide Ring ◽  
Core Motif ◽  
Epoxide Ring Opening ◽  
The Core ◽  
Clinical Drugs ◽  
Benzoyl Chlorides

Background: 1,2,4-triazoles scaffolds display significant biological activities due to hydrogen bonding, solubility, dipole character, and rigidity Objective: The core motif of 1,2,4-triazoles plays a vital role in clinical drugs such as Rizatriptan (anti-migraine), Ribavirin (antiviral), anastrozole (anticancer), etizolam (anxiolytic), estazolam (anticonvulsant), alprazolam (anti-hypnotic), letrozole (aromatase inhibitor), loreclezole (anticonvulsant), trazadone (antidepressant) etc Method: Epoxide ring opening of tert-butyl 6-oxa-3-azabicyclo [3.1.0] hexane-3-carboxylate followed by methylation under basic conditions and de-protection gave the corresponding trans 1-(4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole hydrochloride salt as the precursor. This precursor on reaction with substituted benzoyl chlorides and benzyl bromides gave the desired amide and amine products Results: A library of 14 N-substituted pyrrolidine derivatives i.e. trans3-methoxy-4-(1H-1,2,4-triazol-1-yl) pyrrolidin-1-yl) (phenyl)methanone and trans 1-benzyl-4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole were prepared Conclusion: Eight novel amides (6a-h) and six amines (8a-f) derivatives were synthesized using 1-(4-methoxypyrrolidin-3-yl)-1H-1,2,4-triazole 4 salt with substituted benzoyl chlorides and benzyl bromides.

Synthesis of vinylcyclopropanes by intramolecular epoxide ring opening. Application for an enantioselective synthesis of dictyopterene A

1993 ◽  
Vol 58 (3) ◽  
pp. 626-632 ◽  
Author(s):  
Frank Narjes ◽  
Oliver Bolte ◽  
Detlef Icheln ◽  
Wilfried A. Koenig ◽  
Ernst Schaumann
Keyword(s):  
Ring Opening ◽  
Enantioselective Synthesis ◽  
Epoxide Ring ◽  
Epoxide Ring Opening

Studies on the Total Synthesis of Antibiotic Macrolactin S: A Conventional Approach for the Synthesis of the C1–C9 and C10–C24 Fragments

Synthesis ◽  
2017 ◽  
Vol 50 (03) ◽  
pp. 663-675
Author(s):  
Pabbaraja Srihari ◽  
Ramakrishna Sayini
Keyword(s):  
Total Synthesis ◽  
Nucleophilic Addition ◽  
Ring Opening ◽  
Addition Reaction ◽  
Epoxide Ring ◽  
Epoxide Ring Opening ◽  
Ring Opening Reaction ◽  
Nucleophilic Addition Reaction ◽  
Convergent Approach ◽  
Key Steps

The C1–C9 and C10–C24 segments of the 24-membered polyene macrolide macrolactin S were synthesized by routes involving an epoxide-ring-opening reaction, an Ohira–Bestmann alkyne formation, a chelation-controlled nucleophilic addition reaction, and a Still–Gennari olefination as key steps. A chiron approach , starting from readily available glucose diacetonide, was used to synthesize a key intermediate, and a convergent approach was adopted for the synthesis of the key C10–C24 fragment.

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